Skip Navigation Links The Library of Congress >> Standards
Metadata Encoding and Transmission Standard (METS) Official Web Site

METS_Profile: @xsi:schemaLocation="//www.loc.gov/METS_Profile/ http://www.loc.gov/standards/mets/profile_docs/mets.profile.v1-2.xsd"
title:
ECHO Dep Generic METS Profile for Preservation and Digital Repository Interoperability
abstract:
The primary focus of this profile is to enable repository interoperability and digital preservation of repository content. Because of the strong focus on preservation and not access, this profile is relatively noncommittal regarding file formats or structures. However, special attention has been given to administrative and technical metadata, particularly on integrating the PREMIS data model and schema into METS. Because this profile is agnostic regarding file formats or structures, it is anticipated that this profile may be overlaid on top of or inherited from other profiles which better define these aspects, but require the preservation or interoperability support that this profile can support. As an example refer to the Related Profiles section below.
date:
2005-11-27T00:00:00
contact:
name:
Thomas G. Habing
institution:
University of Illinois at Urbana-Champaign, Grainger Engineering Library Information Center
address:
1301 W. Springfield Ave., Urbana, IL, 61801
phone:
(217) 244-4425
email:
[email protected]
related_profile: @ID="RELATED_PROFILES" @RELATIONSHIP="Inherited by" @URI="WebMETSProfile.xml"
ECHO Dep METS Profile for Web Site Captures
extension_schema:
name:
Metadata Object Description Schema (MODS)
context:
MODS descriptive metadata occur embedded in the dmdSec element. The METS package as a whole must have one primary MODS dmdSec describing the entire package.
extension_schema:
name:
Digital Library Federation / Aquifer Implementation Guidelines for Shareable MODS Records
context:
The Primary descriptive MODS metadata record must conform to these guidelines. In this case conformance means that all requirements of the Aquifer guidelines which are listed as "REQUIRED" or "REQUIRED IF APPLICABLE" must be adhered to by METS files confromant to this profile.
extension_schema:
name:
PREMIS Preservation Metadata Schema: Object
context:
PREMIS Object elements occur embedded in the techMD section. Each file or bitstream which occurs in the file section must have a corresponding PREMIS Object in a techMD section. METS sections which correspond to PREMIS representations, such as structMap element or the METS file overall, may also have an associated PREMIS object element.
extension_schema:
name:
PREMIS Preservation Metadata Schema: Event
context:
PREMIS Event elements occur embedded in the digiprovMD section. PREMIS Events can be associated with nearly any other METS sections, including descriptive metadata, files, structural maps, and possibly others. See the Structural Requirements sections below for details.
extension_schema:
name:
PREMIS Preservation Metadata Schema: Agent
context:
PREMIS Agent elements occur embedded in either the digiprovMD section or rightsMD sections depending on whether the Agent is associated with PREMIS Events or PREMIS Rights.
extension_schema:
name:
PREMIS Preservation Metadata Schema: Rights
context:
PREMIS Rights elements occur embedded in the rightsMD section. Rights can be expressed for files or bitstreams or for descriptive metadata.
extension_schema:
name:
Text Metadata Schema
context:
Any textMD element may be embedded within the administrative techMD element.
extension_schema:
name:
NISO Data Dictionary: Technical Metadata for Digital Still Images (MIX)
context:
Any MIX element may be embedded within the administrative techMD element.
extension_schema:
name:
VIDEOMD: Video Technical Metadata Extension Schema
context:
The VIDEOMD element may be embedded within the administrative techMD element. The VIDEOMD element should include the file_data and physical_data elements, but may include other child elements as well.
extension_schema:
name:
Audio Technical Metadata Extension Schema
context:
The AUDIOMD element may be embedded within the administrative techMD element. The AUDIOMD element should include the file_data and physical_data elements, but may include other child elements as well.
extension_schema:
name:
JHOVE XML Handler Output Schema
context:
JHoVE XML output may be included within the administrative techMD element.
note:
For details on JHOVE see http://hul.harvard.edu/jhove/.
description_rules:
head:
Purpose of this Profile

This profile is generally not concerned with rendering or making accessible any particular representation of an object, but it is concerned with preserving the object and its representations, including the history of how those have changed over periods of time. In this context preservation refers to both short-term interoperability, preserving the representations and metadata as a digital package is moved between two different repositories, but it also refers to the long-term preservation of the package and its history as it exists in various repositories for long periods of time and undergoes various "preservation actions" such as fixity checks, normalizations, or format migrations.

In general this profile is agnostic about almost all aspects of a digital object's representation. We have made some pragmatic concessions, such as mandating at least MODS for the dmdSec, but otherwise don't have many requirements for these sections. However, this profile is very prescriptive when it comes to administrative metadata which can be associated with almost all of the sections that make up the representation, particularly technical and provenance metadata because we feel that those are important to preservation.

head:
Definitions/Assumptions

This profile draws on many of the concepts from the PREMIS data model. In particular, METS documents that conform to this profile are assumed to be "representations" of "intellectual entities." In addition to the overall "representation" that is the METS document itself, there may be subordinate "representations" that correspond to specific structural maps contained in the METS document. In general, the "representation" of an "intellectual entity" is taken to be the combination of the structural maps (structMap), structural map linkings (structLink), descriptive metadata (dmdSec), content files or bitstreams (fileSec), and behaviors (behaviorSec) encapsulated by the METS document. If a METS document contains multiple structural maps, each of those structural maps and associated structural map linkings, descriptive metadata, content files or bitstreams, and behaviors is treated as an alternate representation of the intellectual entity. The administrative metadata (amdSec), including the METS header (metsHdr), is not considered part of the actual representation; however, these sections are critical for interpreting and utilizing the sections that are considered part of the representation. In general, this profile treats data embedded in or referenced from the following METS elements as comprising the representation of the object being preserved: dmdSec, fileSec, structMap, structLink, and behaviorSec. This implies that any of these sections may have associated administrative metadata, particularly entities from PREMIS or one of the technical metadata standards called out in this profile.

The definition of intellectual entities is left for different communities of practice, and will vary across those communities.

One ECHODEP METS document represents a single intellectual entity as defined by the community of practice for which the intellectual entity applies. For example, for one community of practice the intellectual entity of interest may be a web site, but for a different community of practice the intellectual entity of interest may be individual web pages. This profile can be used for either.

Omission of a particular METS section or attribute in this profile does not imply that the section is prohibited by this profile. However, it does imply that the section or attribute may be ignored by a METS processor that claims to conform to this profile. In general, processors that act on METS documents that conform to this profile should attempt to preserve any undefined sections or attributes during any operations performed on the files, such as transformations, submissions, disseminations, or archiving. However, this profile makes no guarantees regarding these undefined sections or attributes.

head: @ID="DESCR_ID"
METS Identifier

Each METS document must be assigned a persistent and globally unique identifier. The only requirement for these identifiers is that they should conform to a widely accepted standard identifier scheme, and they must be locally resolvable, that is the local system must be able to retrieve its local representation of the package using only this identifier. It is desirable that these identifiers also be globally resolvable. However, global resolution is not defined. Acceptable identifier schemes include: OCLC Purls, CNRI Handles, DOIs, and others.

If the METS document is being used as a Submission Information Package (SIP), the identifier is optional. It is assumed that the repository to which the package is being submitted will assign its own identifier. Even if the SIP does have its own identifier, the repository to which it is being submitted may assign a new identifier in which case the SIPs original identifier must be listed as an alternate identifier in the altRecordID section of the header.

As this unique identifier is assumed to be the primary identifier for the METS instance, it must be recorded in the OBJID attribute of the mets element. It is assumed that the OBJID will be assigned at the time the METS file is completed and therefore the CREATEDATE attribute must be the date on which the unique identifier was assigned to the object.

The primary identifier and identifier scheme must also be included in a PREMIS object element as a representation-level description of the entire set of files that are part of the METs object. This PREMIS object element is recorded in a special techMD section with a status of PRIMARY_REPRESENTATION. This techMD section must be referenced via the root div element of the PRIMARY_STRUCTMAP structural map.

head:
PREMIS Identifiers

PREMIS identifiers, namely objectIdentifier, eventIdentifier, agentIdentifier, and permissionStatementIdentifier, may be assigned persistent and globally unique identifier values which conform to a widely accepted standard identifier scheme, similar to the requirement for the METS Identifier. However, there is no requirement that these identifiers be resolvable either globally or by the local system. It is recognized that many systems will not be capable of authoritatively tracking and assigning identifiers to all of the PREMIS entities. Therefore, the only absolute requirement for these identifiers within this profile is that they be consistent within a single METS document, similar to the Rules for XML Identifiers which are described below. If a system is capable of assigning globally unique and persistent identifiers for some PREMIS entities, for example if it maintains an authority file for agents, it should use those identifiers, but this is not a requirement.

Similar to the METS Identifier, an individual repository may reassign its own local identifiers to certain PREMIS entities. If this occurs the original identifier of the entity must be preserved for PREMIS object and agent entities. Both of these entities support multiple identifiers. PREMIS rights and event entities support only a single identifier. Therefore, identifiers which are preassigned to these entities should not be changed.

head:
Descriptive Metadata

This profile makes several assumptions about the descriptive metadata. 1) The most significant assumption is that the descriptive metadata about the entity represented by the METS document are part of the representation of the intellectual entity and not just metadata about the representation. 2) It is also assumed that the descriptive metadata standards supported by different repositories will vary and that preservation of descriptive metadata can help establish the provenance of the METS object. 3) We also assume that the descriptive metadata will change during the life-cycle of the object.

Because of the above assumptions, this profile supports multiple descriptive metadata sections, as well as provenance metadata about each of those sections. However, to facilitate interoperability, this profile requires one primary MODS metadata section.

A potential usage scenario might be a digital object whose original source descriptive metadata is in the MARCXML format. Because this profile requires MODS as the primary descriptive metadata, the MARCXML will be transformed into MODS, and the MODS will be stored in the METS document along with a provenance statement with some details about the transformation, especially identifying the source metadata format. However, because descriptive metadata are considered to be a significant part of the representation of an entity and because transformations between metadata formats are often imperfect, the original MARCXML format is also stored in the METS document as an alternate metadata format. Now assume that the digital object is to be ingested into DSpace. However, DSpace does not have native support for the MODS metadata format; therefore, as part of the ingest process the MODS must be transformed into the idiosyncratic Dublin Core metadata format that is supported by DSpace. This metadata format is also added as another alternate descriptive metadata format to the METS documents, along with a provenance statement describing how this new DC format was derived from the primary MODS format. Now imagine that the object exists in DSpace for some period of time during which the descriptive metadata undergoes some revision, such as the addition of new subject terms or the addition of an abstract. Also imagine that the object is being disseminated from DSpace for ingest into some new repository. This could trigger the addition of another alternate descriptive metadata section to the METS document. This alternate format would conform to the idiosyncratic DSpace Dublin Core format, but the provenance statement would specify that this DC format represents a newer version of the descriptive metadata than was originally ingested into DSpace. The above scenario would produce a chain of descriptive metadata formats, such as MARCXML (original) -> MODS (primary) -> DC (version 1) -> DC (version 2), with the provenance statements adequate to determine the sequence of events that led to this chain. As part of this profile we also envision future processes that might reconcile later metadata revisions and merge those revisions back into a new primary MODS descriptive metadata section.

It must be noted that even though this profile can accommodate multiple different versions of the same descriptive metadata, it does not mandate that every change to the descriptive metadata must be preserved as an alternate version. The tools that we are developing (the Hub and Spoke) will take advantage of this feature especially for the descriptive metadata which our tool may transform in significant ways. Just as you would probably not delete a source content file after doing a format migration to a more 'preservable' format (say from TIF to JPEG2000), we also assume that you will not delete descriptive metadata or a structural map just because you have migrated to a new format or version (say MARC to MODS or even from MODS to MODS with a new revised abstract).

It will be up to a particular system developer and/or collection curator as to what extent to implement this. In general, you would not want to preserve an old version of the descriptive metadata every time a new subject term was added or a spelling mistake was corrected, but if the descriptive metadata was substantially rewritten because of new scholarly discoveries about the object, this probably would require preserving the old metadata along with a provenance statement describing the rational for the changes in the new metadata. Likewise, a transformation into an entirely new metadata format should require a new alternate metadata version with the original also preserved for posterity.

Part of the assumptions of this profile is that the objects being packaged are in some sort of "preservation state" -- a deliberate decision was made by some agent to put the object into that state, and the object is not expected to be undergoing frequent changes.

For more details see the structural requirements section for descriptive metadata below.

head: @ID="STRUCT_MAP"
Structural Map

This profile also makes assumptions about the structural maps which are similar to the assumptions about descriptive metadata. 1) The structural maps of the object represented by the METS document are also considered a significant parts of the representation itself. 2) In addition, the level of support for complex structural maps can vary greatly across different repositories, meaning that complex structural maps will often need to be transformed or simplified in order to ingest the object into a specific repository. 3) To a lesser extent, we also assume that structural maps can change over time.

Just as with the descriptive metadata, this implies that this profile must support multiple structural maps along with provenance metadata about each of those structural maps. Unlike the descriptive metadata, we cannot specify a single interoperable standard that a primary structural map must follow. This is because there are currently no standards for structural maps which are rich enough to represent all possible structures to which an object might conform. Because of this,and also because access and rendering are not a primary focus for this profile, we are deliberately vague with respect to structural maps (Other profiles which inherit from this profile may be more prescriptive with regard to structural maps. See the Related Profiles section above for an example.). In general we cannot be any more prescriptive about structural maps than we can be for content files.

As an example, if a digital object representation requires the Indiana METS Navigator that would be the structural map it should use; alternately it could require the Harvard Page Delivery Service (PDS), or it might have a separate structural map for each application. At some future point a new and better page turning application may emerge that requires a new structural map. Now the METS document would contain both the old structural map and the new with appropriate technical and provenance metadata, so that a future curator could make informed decisions about the object and its possible representations.

However, this profile does still specify that there must be one structural map which is considered the primary structural map for the object. This primary structural map is defined to be that structure that provides the best representation for the digital object as determined by the original creator of the structural map. If the METS document contains multiple structural maps, a processing system may choose amongst the various structural maps that best meets its needs; however, preference should be given to the primary structMap if no other clearly meets the requirements of the system. The primary structural map should also have a reference to every file in the file section.

Since our profile is not so concerned with the actual structural map, but with how that structural map can be described for preservation, thus unlike many other profiles, we recommend that structural maps have associated administrative metadata, both technical and provenance, to facilitate the long term preservation of the structural map, regardless of what the structure actually is.

head:
Structural Map Linking

Because this profile interprets structural maps as representations of intellectual entities, and multiple structural maps in the same METS document as alternate representations of the same entity, we have imposed a restriction that structural map linking must only link divisions within a single structural map. Using structural map linking to link divisions across different structural maps is forbidden. This allows a single structural map linking section to be associated with a single representation and by extension any administrative metadata associated with a structural map is assumed to also apply to the associated structural map linking section.

head:
Rules for the XML

Every METS XML file conforming to this profile must be UTF-8 encoded Unicode.

Every METS XML file conforming to this profile must begin with the standard XML declaration:

<?xml version="1.0" encoding="UTF-8"?>.

head: @ID="XML_IDS_RULE"
Rules for XML Identifiers

By XML identifiers we mean any XML attribute of type ID and by extension attributes of type IDREF or IDREFS. This includes those attributes which occur in the METS namespace itself and any other extension schema that may be used within the METS document. This profile makes no requirements for those types of identifiers beyond the requirements that are already specified by the XML specification itself. All values of ID-type attributes must be unique within the METS document. However, they may be reused in different METS documents, i.e. they need not be globally unique. They might also be different in different instances of the METS document for the same object, i.e. they need not be globally persistent. In other words, attributes of type ID (also IDREF and IDREFS) have no meaning outside the METS document.

Also, the syntax used for those identifiers is not specified beyond what is already required by the XML specification. It may be convenient for systems that are creating METS documents to adopt naming standards for ID-type attributes, such as all amdSec ID attributes must begin with "AMD_" followed by a sequential number. However, this is not a requirement of this profile, and systems which are processing METS documents based on this profile should make no assumptions in this regard.

Finally, the schema for METS specifies that certain ID attributes are required on certain elements, and those requirements must be followed. However, in general this profile only requires an ID-type attribute on an element if that element is referred to via an IDREF or IDREFS-type attribute elsewhere in the file.

head:
Date Values

Unless otherwise specified (or constrained by the XML Schema) all date values must conform to the W3C-DTF format with a granularity of at least days, such as YYYY-MM-DD. Finer granularities are acceptable, such as YYYY-MM-DDTHH:MM:SS, but lesser granularities are not acceptable, such as YYYY-MM or YYYY. Note that all date attributes specified in the METS profile itself require the xsd:dateTime format which is YYYY-MM-DDTHH:MM:SS with an optional time zone indicator.

head: @ID="LINK_VS_EMBED"
Linking Versus Embedding

In general this profile encourages metadata to be embedded within the METS document via the mdWrap element. However, in some cases, if there is a good reason, for example if the metadata is too large to conveniently embed, it may be referenced via an mdRef. If mdRef is used the xlink:href must be a relative URL which is relative to the location of the METS document itself. The same metadata must not be both embedded and referenced. Each metadata section must have either an mdWrap or an mdRef but not both.

Conversely, this profile encourages content to be referenced via the FLocat element. The FLocat xlink:href must be a relative URL which is relative to the location of the METS document itself. However, if embedding the content would make the package easier to move around and share and would not cause the METS document to become too large then it may be embedded via the FContent element. The same content may not be both embedded and referenced. Each file element must have either an FLocat or an FContent but not both.

controlled_vocabularies:
vocabulary:
name:
PREMIS Suggested Event Types
maintenance_agency:
Library of Congress
values:
value:
CAPTURE = the process whereby a repository actively obtains an object
value:
COMPRESSION = the process of coding data to save storage space or transmission time
value:
DEACCESSION = the process of removing an object from the inventory of a repository
value:
DECOMPRESSION = the process of reversing the effects of compression
value:
DECRYPTION = the process of converting encrypted data to plain text
value:
DELETION = the process of removing an object from repository storage
value:
DIGITAL_SIGNATURE_VALIDATION = the process of determining that a decrypted digital signature matches an expected value
value:
DISSEMINATION = the process of retrieving an object from repository storage and making it available to users
value:
FIXITY_CHECK = the process of verifying that an object has not been changed in a given period
value:
INGESTION = the process of adding objects to a preservation repository
value:
MESSAGE_DIGEST CALCULATION = the process by which a message digest ("hash") is created
value:
MIGRATION = a transformation of an object creating a version in a more contemporary format
value:
NORMALIZATION = a transformation of an object creating a version more conducive to preservation
value:
REPLICATION = the process of creating a copy of an object that is, bit-wise, identical to the original
value:
VALIDATION = the process of comparing an object with a standard and noting compliance or exceptions
value:
VIRUS_CHECK = the process of scanning a file for malicious programs
context:

PREMIS Suggested Event Types are used as values for the eventType element which is used for the METS digiprovMD sections.

vocabulary:
name:
Event Types for Descriptive Metadata
maintenance_agency:
The ECHO DEPository Project
values:
value:
METADATA_TRANSFORMATION = the transformation of one metadata format into another
value:
METADATA_CREATION = the creation of a new metadata record
value:
METADATA_MODIFICATION = the modification of a metadata record that does not change the format
value:
METADATA_DELETION = the deletion of a metadata record
context:

Event types which are used for describing actions performed on the descriptive metadata of a package.

vocabulary:
name:
Event Types for Structural Maps
maintenance_agency:
The ECHO DEPository Project
values:
value:
STRUCTMAP_TRANSFORMATION = changes to a structural map which effect the compatibility with processing systems
value:
STRUCTMAP_CREATION = the creation of a new structural map
value:
STRUCTMAP_MODIFICATION = changes to a structural map which do not effect the compatibility with processing systems
value:
STRUCTMAP_DELETION = the deletion of a structural map
context:

Event types which are used for describing actions performed on the structural map of a package.

description:

The difference between STRUCTMAP_TRANSFORMATION and STRUCTMAP_MODIFICATION is dependent on the system which will process the structural map. Changes that do not effect the ability of systems that could process the old version to process this version should be given an eventType of STRUCTMAP_MODIFICATION. However, changes that make the structural map no longer compatible with systems which were able to process the original structural map should be given an eventType of STRUCTMAP_TRANSFORMATION.

vocabulary:
name:
PREMIS Suggested Object Categories
maintenance_agency:
Library of Congress
values:
value:
REPRESENTATION
value:
FILE
value:
BITSTREAM
context:

PREMIS Suggested Object Categories are used as values for the objectCategory element which is used for the METS techMD sections.

vocabulary:
name:
PREMIS Suggested Agent Types
maintenance_agency:
Library of Congress
values:
value:
PERSON
value:
ORGANIZATION
value:
SOFTWARE
context:

PREMIS Suggested Agent Types are used as values for the PREMIS agent/agentType element which is used for either METS digiprovMD or rightsMD sections.

vocabulary:
name:
Descriptive Metadata Status
values:
value:
PRIMARY_DMDSEC
value:
ALTERNATE_DMDSEC
context:

Used with the STATUS attribute of dmdSec elements. There must be only one dmdSec element with a STATUS of PRIMARY_DMDSEC, but there can be any number of dmdSec elements with a STATUS of ALTERNATE_DMDSEC.

vocabulary:
name:
Structural Map Type
values:
value:
PRIMARY_STRUCTMAP
context:

Used with the TYPE attribute of structMap element to indicate that this structMap should be considered the primary structural map for the METS file. There must be only one structMap element with a TYPE of PRIMARY_STRUCTMAP.

vocabulary: @ID="PRIMARY_REPRESENTATION"
name:
Technical Metadata Status
values:
value:
PRIMARY_REPRESENTATION
context:

Used with the STATUS attribute of techMD elements. Used to indicate that a techMD section contains a PREMIS object element which describes the entire METS document as a whole. There should only be one techMD with this status, and it must contain a PREMIS object element which describes a representation.

vocabulary:
name:
PREMIS Identifier Types
values:
value:
LOCAL
value:
PURL
value:
HANDLE
value:
DOI
context:

These values should be used for any PREMIS *IdentifierType. The value LOCAL should be used whenever the corresponding *IdentifierValue contains an identifier which is local to just this METS file, usually this value will be the same as the XML ID attribute value. These values do not constitute an exhaustive list, but they correspond to the METS LOCTYPE attribute values and should be used whenever applicable. The value OTHER should not be used; instead just name the other type.

vocabulary:
name:
PREMIS linkingAgentRole Values
values:
value:
EVENT_INITIATOR = the agent who requested or initiated the event
value:
SOFTWARE_USED = the software system used to carry out the event
value:
DATA_SOURCE = the source of the data or metadata used by the event
value:
DATA_DESTINATION = where the data or metadata resides after the event completes
context:

These values do not constitute an exhaustive list but should be used when they apply. Other values may be used if a value given above does not seem to apply.

structural_requirements:
metsRootElement:
requirement: @ID="ROOT_OBJID" @RELATEDMAT="DESCR_ID APP1_METS_SAMPLE_1"
head:
OBJID

As previously described, the OBJID attribute must be the primary, persistent, and globally unique identifier for the file. This attribute is required; all METS files which are conformant to this profile must have a persistent and globally unique identifier, unless they are Submission Information Packages that will be assigned an identifier upon ingestion.

Computing systems which process files conformant to this profile must preserve this identifier through any transformations, submissions, disseminations, archiving, or other operations on the file. If a system does reassign a new primary identifier to the METS document, the old identifier must be listed as an altRecordID in the metsHdr. The alternate identifiers must also be recorded in the PRIMARY_REPRESENTATION techMD section.

requirement:
head:
LABEL

The LABEL attribute must contain a human-readable title string that would be suitable for distinguishing the METS document from others when a person is browsing through a list of METS documents. This value could be a title element or variation thereof taken from the dmdSec. This attribute is required.

requirement:
head:
PROFILE

The PROFILE attribute must contain the URI assigned to this profile when it was registered with the Library or Congress. The value is '//www.loc.gov/mets/profiles/00000015.xml'. This attribute is required.

metsHdr:
requirement: @RELATEDMAT="DESCR_ID APP1_METS_SAMPLE_2"
head:
CREATEDATE

This date must be the date on which the METS document was assigned its first persistent, globally unique identifier, even if the actual file itself was created prior to this date, or even if the file was not yet created when the identifier was coined. This attribute is required. Once it is assigned it must not be changed, even if the OBJID is changed.

Computing systems which process files conformant to this profile must preserve this date through any transformations, submissions, disseminations, archiving, or other operations on the file.

requirement:
head:
LASTMODDATE

This date must reflect the date on which any changes to the METS document itself occur. This attribute is required, even for newly created METS documents, in which case the CREATEDATE and the LASTMODDATE should match. Subsequently, the LASTMODDATE must always be after the CREATEDATE.

requirement: @RELATEDMAT="DESCR_ID ROOT_OBJID"
head:
altRecordID

There can be altRecordID elements. If the primary identifier of the METS document as recorded in the OBJID element of the mets root element ever changes for any reason, the previous identifier must be recorded as an alternate identifier in the altRecordID element.

Computing systems which process files conformant to this profile must preserve all altRecordID elements through any transformations, submissions, disseminations, archiving, or other operations on the file.

dmdSec:
requirement: @RELATEDMAT="DMD_DIGIPROV LINK_VS_EMBED"
head:
All Descriptive Metadata

All descriptive metadata should be embedded in the dmdSec via the mdWrap element, but may be referenced via the mdRef if it is too large to conveniently embed. The same metadata must not be both embedded and referenced.

Each dmdSec, including the primary MODS dmdSec, must have a CREATED attribute which reflects the date on which description was created.

Each dmdSec, including the primary one, must have an ADMID attribute that references a digiprovMD section. See the requirements for the amdSec for details. Additional administrative metadata sections may be referenced, but the digiprovMD reference is required.

The STATUS attributes defined by this profile are 'PRIMARY_DMDSEC' or 'ALTERNATE_DMDSEC'. There must be one and only one dmdSec with a STATUS='PRIMARY_DMDSEC'. There may be zero or more dmdSec elements with a STATUS='ALTERNATE_DMDSEC'.

All dmdSec elements with a STATUS of PRIMARY_DMDSEC or ALTERNATE_DMDSEC must be considered descriptive of the entire intellectual entity represented by the METS document. The first div child in all structMap elements must have a DMDID attribute that references all the PRIMARY_DMDSEC and ALTERNATE_DMDSEC dmdSec elements.

Computing systems which process files conformant to this profile must preserve the PRIMARY_DMDSEC and ALTERNATE_DMDSEC dmdSec through any transformations, submissions, disseminations, archiving, or other operations on the file. Although, the PRIMARY_DMDSEC dmdSec may be modified so long as previous states are preserved in alternate dmdSec elements along with appropriate provenance metadata.

There may be other dmdSec elements with STATUS values other than PRIMARY_DMDSEC or ALTERNATE_DMDSEC; however, these are undefined by this profile. Computing systems which process files conformant to this profile should preserve these dmdSec through any transformations, submissions, disseminations, archiving, or other operations on the file, but this behavior is not guaranteed.

requirement:
head:
Primary Descriptive Metadata

Every METS document must contain exactly one dmdSec with a STATUS attribute of 'PRIMARY_DMDSEC'. This primary dmdSec must have an embedded MODS XML metadata record. The MODS must be embedded via mdWrap and xmlData elements. The primary MODS metadata must not be referenced via an mdRef.

The primary dmdSec describes the entire intellectual entity represented by the METS document.

The primary MODS descriptive metadata must conform to the Digital Library Federation / Aquifer Implementation Guidelines for Shareable MODS Records. [http://www.diglib.org/aquifer/dlfmodsimplementationguidelines_finalnov2006.pdf]. All requirements in the Aquifer guidelines listed as "REQUIRED" or "REQUIRED IF APPLICABLE" must be adhered to by METS files confromant to this profile.

Computing systems which process files conformant to this profile must be able to process the MODS descriptive metadata in the primary dmdSec. The primary dmdSec should be a processing system's first source for any required descriptive metadata about the object. However, if a processing system is able to determine that for its purposes more suitable descriptive metadata is available from one of the alternate dmdSec elements it may use that instead.

The primary descriptive metadata about an object is expected to change over time as objects are submitted, subsequently transformed, or disseminated by different repositories. However, anytime that the primary descriptive metadata for a repository is changed or replaced with new data, the original primary dmdSec should be preserved and its STATUS changed to 'ALTERNATE_DMDSEC', and the newer version should be given a STATUS of 'PRIMARY_DMDSEC'. In other words, at any one time there must be exactly one primary dmdSec element with embedded MODS. However, there may be any number of alternate dmdSec elements with embedded MODS which may represent earlier versions of the descriptive metadata. See the following section on Alternate Descriptive Metadata for more details on alternate dmdSec elements.

Any time the primary dmdSec is modified the referencing digiprovMD must be modified to describe the the nature of the changes.

If the primary object being represented by this METS document contains constituent parts which also must have some level of descriptive metadata, the MODS element should contain relatedItem elements for each subpart. Each relatedItem element must have an ID attribute and a type="constituent" attribute. The relatedItem element must be referenced via a DMDID attribute on the associated structMap div elements which represent the constituent part. A typical use for relatedItem elements might be a web capture where the individual resources making up the web capture each have there own descriptive metadata, such as the title of the web page.

requirement:
head:
Alternate Descriptive Metadata

A METS document may contain one or more alternate dmdSec. These should be embedded via mdWrap, but may be referenced via mdRef.

The STATUS attribute of the alternate dmdSec must be 'ALTERNATE_DMDSEC'.

Alternate dmdSec describe the entire intellectual entity represented by the METS document.

Alternate dmdSec are intended primarily to provide an historical record of the descriptive metadata for an object. This includes historical versions of the primary MODS metadata, and also historical versions of alternate metadata formats that might exist for the object at different points in time. For example, if the object was originally described using MARCXML, that MARCXML can be transformed into MODS which becomes the primary dmdSec, but the original MARCXML can be preserved in an alternate dmdSec. If the METS document is subsequently ingested and later disseminated from a repository whose native metadata format is Dublin Core, the Dublin Core metadata would be added to the METS document as another alternate dmdSec.

Because of how the alternate dmdSec are intended to provide historical versions of the descriptive metadata, computing systems which process files conformant to this profile must preserve the alternate dmdSec through any transformations, submissions, disseminations, archiving, or other operations on the file.

amdSec:
requirement:
head:
General Requirements for the Organization of Administrative Metadata

In general this profile assumes a single amdSec element for the entire METS document. However, this is not an absolute requirement. How techMD, digiprovMD, sourceMD, and rightsMD elements are arranged beneath one or more admSec elements is not significant and can be at the convenience of the original creator of the file so long as the result conforms to the METS XML schema.

The reason that the arrangement of sub-elements beneath one or more admSec elements is not significant is that this profile requires all ADMID attributes (of type IDREFS) to point directly to techMD, digiprovMD, sourceMD, or rightsMD elements via those elements' ID attributes. An ADMID attribute must not point to an enclosing admSec, but directly to the relevant sub-element. In addition, if there are relationships between the sub-elements themselves, such as a digiprovMD that contains a PREMIS event and another digiprovMD that contains a PREMIS agent associated with that event, the relationships between those sub-elements must be explicitly defined via identifier and referencing mechanisms explicit in the markup itself, such as the PREMIS event linkingAgentIdentifier and corresponding PREMIS agent agentIdentifier. These relationships cannot be implied merely because of the nesting or sequence of sub-elements beneath one or more amdSec elements. These linking mechanisms will be more fully described in separate sections below.

requirement:
head:
General Requirements for the Use of PREMIS

PREMIS object, event, agent, and rights elements may all be used in various different amdSec sub-elements. However, the PREMIS container element <premis> is never used. Furthermore, only a single PREMIS object, event, agent, or rights element may ever be embedded within a single amdSec sub-element. For example, a techMD may only contain a single object element; it may not contain multiple object elements or an object element and some element like mix. Even, if a single file needs to reference multiple technical metadata sections, each of those metadata sections must be wrapped in its own techMD section. The same applies to other administrative metadata sections. In general, PREMIS object elements are embedded under techMD, PREMIS event elements are embedded under digiprovMD, PREMIS rights elements are embedded under rightsMD, and PREMIS agent elements are embedded under either digiprovMD or rightsMD depending on whether the agent is associated with an event or with rights. If the same agent is associated with multiple events or rights it must occur only once. If the same agent is associated with both an event and a rights element, it may occur under either the digiprovMD or rightsMD section; it does not matter which.

The linkage between a METS section, such as file, and a PREMIS entity, such as object, is via the METS ID attribute of the amdSec sub-element, such as techMD, containing the PREMIS entity and ADMID attribute of the section which is linking to the PREMIS entity. For example, a file element which references a PREMIS object entity would have a ADMID attribute containing the ID of the techMD section which contains the PREMIS object entity.

The linkages between related PREMIS entities, such as events and agents or rights and agents, must be via the PREMIS IDREF-type (LinkAgentXmlID, GrantAgentXmlID, etc.) attributes and the METS ID of the amdSec sub-element which contains the agent. Specifically, the relationship between an event and the associated agents is made by assigning the value of the ID attribute of the amdSec sub-element containing the agent to the LinkAgentXmlID attribute of the event, and similarly for rights and agents. There are several reasons that these linkages are made via the ID-type and IDREF-type attributes instead of between the identifier elements (objectIdentifier, eventIdentifier, agentIdentifier, and permissionStatementIdentifier) of the various PREMIS entities. One reason is for consistency with the METS way of linking items which relies on ID-type and IDREFS-type attributes. A second reason is that the PREMIS object and agent entities may have more than one identifier which could complicate the processing of the associations. A third reason is that by using the ID-type and IDREF-type attributes you can rely on the XML validation mechanisms to ensure that the usage of the ID-type and IDREF-type attributes are consistent. An XML validator can ensure that each ID-type attribute used within a single XML document is unique, and it can also ensure that each IDREF-type or IDREFS-type attribute value has a corresponding ID-type attribute somewhere in the same XML document.

requirement:
head:
Technical Metadata (techMD)

This profile supports several different types of technical metadata. PREMIS object elements with an objectCategory of FILE or BITSTREAM should be associated with file elements in the fileSec. PREMIS object elements with an objectCategory of REPRESENTATION may be associated with div elements in a structMap. In addition to PREMIS object elements, various format-specific technical metadata schema have been adopted for different formats of files or bitstreams. These should be associated with file elements in the fileSec, depending on the format of the file. Finally, the XML output of JHOVE may be associated with file elements in the fileSec. See the following requirements for more detail.

requirement:
head:
Technical Metadata for Files and Bitstreams

Each file or bitstream which is referenced or embedded in the fileSec must have a corresponding techMD section.

The content of the techMD section must be a PREMIS object element embedded in the techMD via the mdWrap element. The PREMIS object element must conform to the XML Schema of PREMIS.

The PREMIS objectIdentifier elements must have values that correspond to the OWNERID attribute of the referencing file element.

The PREMIS objectCategory element must have a value of 'FILE' or 'BITSTREAM'.

One PREMIS objectCharacteristics element is required with a compositionLevel element value of 0. Composed objects must be decomposed prior to being included in packages conforming to this profile. Therefore, compositionLevel elements other than 0 are prohibited. Note that in keeping with recommendations from PREMIS both ARC files and documents contained in ARC files are all described at compositionLevel 0.

The objectCharacteristics element must have at least one fixity sub-element which has a messageDigestAlgorithm of 'SHA-1'. The value contained in the messageDigest must match the value of the CHECKSUM attribute of the referencing file element. There may be additional fixity sub-elements with different messageDigestAlgorithm values.

The objectCharacteristics element must have a size sub-element. The value of this sub-element must be a positive integer number representing the size in bytes of the file or bitstream. This value must match the SIZE attribute of the referencing file element.

The objectCharacteristics element must have a format sub-element which has a formatDesignation child element which in turn has a formatName child element. The value of the formatName element must be the MIME type value of the file or bitstream. It must match the MIMETYPE attribute of the referencing file element and follow the same rules. It is recommended that if there are format registries describing the format of the file or bitstream that the format sub-element may have one or more formatRegistry sub-elements referencing the appropriate registry key.

A conforming METS document may contain additional PREMIS object entity elements.

Technical metadata for files or bitstreams must conform to the specific technical metadata for its root MIME type specified in MIME Type technical metadata requirements.

requirement:
head:
Technical Metadata for Files with a Root MIME Type of 'Text'

In addition to required elements specified in Technical Metadata for Files and Bitstreams, all files with a root MIME type of 'text' should provide a second techMD section in addition to the PREMIS section previously mentioned. This second techMD section must wrap a textMD description of the file.

It is strongly recommended that text MIME types, specifically text/xml, that conform to external schema or DTDs record schema information using PREMIS Dependency elements.

requirement:
head:
Technical Metadata for Files with a Root MIME Type of 'Image'

In addition to required elements specified in Technical Metadata for files and bitstreams, all files with a root MIME type of "image" should provide a second techMD section in addition to the PREMIS section previously mentioned. This second techMD section must wrap a MIX Schema description of the file.

requirement:
head:
Technical Metadata for Files with a Root MIME Type of 'Audio'

In addition to required elements specified in Technical Metadata for files and bitstreams, all files with a root MIME type of 'audio' should provide a second techMD section in addition to the PREMIS section previously mentioned. This second techMD section must wrap a AUDIOMD element from the Library of Congress' Audio Metadata Schema. The AUDIOMD element must contain a file_data child element, should contain a physical_data element, but may contain other elements as well as allowed by the XML schema.

requirement:
head:
Technical Metadata for Files with a Root MIME Type of 'Video'

In addition to required elements specified in Technical Metadata for files and bitstreams, all files with a root MIME type of 'video' should provide a second techMD section in addition to the PREMIS section previously mentioned. This second techMD section must wrap a VIDEOMD element from the Library of Congress Video Metadata Schema. The VIDEOMD element must contain a file_data child element, and should contain a physical_data element, but may contain other elements as well as allowed by the XML schema.

requirement:
head:
Technical Metadata for Files with a Root MIME Type of 'Application'

In addition to required elements specified in Technical Metadata for files and bitstreams, all files with a root MIME type of 'application' must include in the previously described PREMIS techMD section a PREMIS creatingApplication, software and environment elements.

requirement:
head:
JHOVE

As an alternative or in addition to the technical metadata described above which is specific to a file format, the XML output of the JHOVE application may be embedded in a techMD section which is referenced from a file. [http://hul.harvard.edu/jhove/]

requirement:
head:
Technical Metadata Associated with Representations

In addition to the technical metadata associated with files or bitstreams, this profile also allows technical metadata to be associated with representations. This profile considers the entire METS file itself to be one 'super' representation, but it also considers each structMap in the METS file to be a representation as well. A special techMD with a status of PRIMARY_REPRESENTATION must be present in each METS file. This techMD section must embed a PREMIS object element with an objectCategory of REPRESENTATION. This techMD section must be referenced via the root div element of the primary structMap.

In addition to the PRIMARY_REPRESENTATION, other representation-level technical metadata sections with embedded PREMIS object elements with an objectCategory of REPRESENTATION may be included and referenced from other structMap div elements. In certain cases it may also be useful to reference these representation-level technical metadata sections from file elements.

requirement:
head:
Rights Metadata (rightsMD)

This profile does not require any particular rights metadata. However, if rights statements are used, it is recommended to use the PREMIS rights element. Regardless of how rights are specified, this profile does require systems processing files which are conformant to this profile to preserve all rights statements and their linkages to other sections during any actions performed on the METS file.

requirement:
head:
Source Metadata (sourceMD)

This profile has no requirements for this section, but processing systems which conform to this profile should preserve any sourceMD elements along with their linkages to other sections during any actions performed on the METS file.

requirement:
head:
Digital Provenance Metadata (digiprovMD)

In general, any element with an ADMID attribute may reference a digiprovMD element. This profile requires provenance for the primary and alternate descriptive metadata sections. It encourages provenance for files and bitstreams and structural maps, and it allows provenance in other sections. All provenance statements must be expressed using the PREMIS event element and possibly associated PREMIS agent elements.

requirement: @ID="DMD_DIGIPROV"
head:
Provenance for Descriptive Metadata

As previously noted in the structural requirements for dmdSec elements, each dmdSec which has a STATUS of 'PRIMARY_DMDSEC' or 'ALTERNATE_DMDSEC' must have a corresponding digiprovMD section.

The content of this digiprovMD must be a PREMIS event element embedded in the digiprovMD via the mdWrap element. The PREMIS event must have an eventType of 'METADATA_TRANSFORMATION', 'METADATA_CREATION', 'METADATA_MODIFICATION', or METADATA_DELETION. It should have an eventDetail which describes how the metadata was derived, transformed, or modified and it should have an linkingAgentIdentifier which identifies the agent responsible for the transformation or creation of the descriptive metadata. The PREMIS event and agent elements must conform to the XML Schema of PREMIS.

There are two ways to delete descriptive metadata using the METADATA_DELETION eventType. In the first way the metadata is just marked as deleted, but it continues to be maintained in the METS document. This is accomplished by referencing a digiprovMD with a PREMIS event element with an eventType of METADATA_DELETION. Even though the metadata is still contained in the document for all intents and purposes it should be treated as if were deleted -- it would not appear in any disseminations of the entity, except possibly for privileged administrative users. The second way is to actually delete the metadata. In this case just the mdRef or mdWrap elements are deleted from the dmdSec, leaving it empty. The dmdSec element needs to be maintained so that it can reference the digiprovMD with a PREMIS event element with an eventType of METADATA_DELETION. The dmdSec also needs to be maintained to avoid dangling IDREF attributes which may have pointed to the now deleted metadata. Because of the possibility of deleted metadata, processing systems will need to take care to check any provenance statements associated with the metadata before disseminating it to users or other systems.

requirement:
head:
Provenance for Files and Bitstreams

Each file or bitstream which is referenced or embedded in the fileSec may have one or more corresponding digiprovMD sections.

The content of this digiprovMD must be a PREMIS event element embedded in the digiprovMD via the mdWrap element. The PREMIS event should use an eventType from the list of PREMIS Suggested Event Types when ever possible. It should have an linkingAgentIdentifier which identifies the agent responsible for the event. The PREMIS event and agent elements must conform to the XML Schema of PREMIS.

Just as with descriptive metadata, files may be deleted, and file deletions should be indicated in the same way as for descriptive metadata. Files may be kept in the METS document but marked as deleted by referencing a digiprovMD with a PREMIS event with an eventType of DELETION. The file may also be deleted by removing all child elements below the file element, but keeping the file element itself so that it can reference a digiprovMD with a PREMIS event element with an eventType of DELETION. In either case, processing systems must take care to check the DELETION status of any files before attempting to disseminate or process them in any way.

requirement:
head:
Provenance for Structural Maps

The first div child element of each structMap should reference a digiprovMD section.

The content of this digiprovMD must be a PREMIS event element embedded in the digiprovMD via the mdWrap element. The PREMIS event must have an eventType of 'STRUCTMAP_TRANSFORMATION', 'STRUCTMAP_CREATION', 'STRUCTMAP_MODIFICATION', or 'STRUCTMAP_DELETION'. It should have an eventDetail which describes how the structural map was derived, transformed, or modified and it should have an linkingAgentIdentifier which identifies the agent responsible for the transformation or creation of the structural map. The PREMIS event and agent elements must conform to the XML Schema of PREMIS.

There are two ways to delete a structural map using the METADATA_DELETION eventType. In the first way the structural map is just marked as deleted, but it continues to be maintained in the METS document. This is accomplished by referencing, from the root div element of the structMap, a digiprovMD with a PREMIS event element with an eventType of METADATA_DELETION. Even though the structural map is still contained in the document for all intents and purposes it should be treated as if were deleted -- it would not appear in any disseminations of the entity, except possibly for privileged administrative users. The second way is to actually delete the structural map. In this case all of the div elements below the root div element are removed. The root div element needs to be maintained so that it can reference the digiprovMD with a PREMIS event element with an eventType of METADATA_DELETION.

requirement:
head:
PREMIS Agent Entities

PREMIS Agent entities which are associated with PREMIS Events will be embedded in their own digiprovMD via the mdWrap element. The connection between the event and the agent must be maintained via the ID attribute of the digiprovMD element containing the agent and the LinkAgentXmlID attribute of the linkingAgentIdentifier element in the event element.

PREMIS Agent entities which are associated with PREMIS Rights will be embedded in their own rightsMD via the mdWrap element. The connection between the rights and the agent must be maintained via the ID attribute of the digiprovMD element containing the agent and the GrantAgentXmlID attribute of the grantingAgent element in the rights element.

If the same Agent is associated with multiple Events or Rights it should still only occur once in the METS document.

In the unlikely event that the same PREMIS Agent entity is associated with both an Event entity and a Rights entity, it should still just occur once, and it can be embedded in either a METS digiprovMD or a METS rightsMD section.

fileSec:
requirement:
head:
General Rules for File Groups and Files

There may be more than one fileGrp element inside the fileSec, and fileGrp elements may be nested. However, similar to the rules for multiple amdSec elements, this profile attaches no meaning to how fileGrp elements are arranged or nested. All linkages between sections are through the file or stream elements and not via the fileGrp elements. This profile essentially treats all file elements as if they were contained inside a single fileGrp. If multiple fileGrp elements are used processors conformant to this profile should preserve them, but this behavior is not guaranteed.

The fileGrp elements must contain a file element for each file which comprises the digital object.

Even though this profile is mostly concerned with files, individual streams within a file such as separate audio streams and video streams in a movie file may be delineated using the stream element if these individual streams have unique structural requirements which are not inherent in the file itself or if they require their own descriptive or administrative metadata. This profile requires that stream elements and associated metadata are preserved during actions performed on the METS file, but processors aren't required to act on these data. The stream element must not be used to describe what are essentially separate files contained in any kind of archive file such as a Zip or Tar file.

All the files which comprise the package must exists in the same location as the METS document itself or in subdirectories under the location where the METS document resides. These files are referenced via the Flocat element.

requirement:
head:
Requirements for all file elements

The MIMETYPE attribute must be included. For text types, this must include the charset portion if available. If the initial type is known to be text, but the subtype is not known, then a value of "text/plain" must be used. If nothing about the MIME Type is known then the value of "application/octet-stream" must be used.

The SIZE attribute must be included. This value must match the actual number of bytes in the file.

The CREATED attribute must be included. If the actual original creation date of the file is known that value must be used. If the original creation date of the file is not known then the date on which the file was added to the METS package must be used.

The CHECKSUM attribute must contain the SHA-1 checksum generated for the file. The checksum must be represented as a 40-digit hexadecimal string. The CHECKSUMTYPE attribute must have a value of 'SHA-1'.

The OWNERID attribute may contain a globally unique and persistent identifier that meets the criteria set forth in the parent METS profile for identifiers.

The ADMID attribute must be present. It must refer back to any techMD elements containing technical metadata about each file. This includes the required PREMIS techMD section and the additional MIME type specific techMD section. It must also refer back to any digiprovMD sections associated with the file. See the requirements under the amdSec above for details.

Each file element represents one file which composes the object.

The file element must contain an FLocat element which points to the file. The FLocat must have a LOCTYPE attribute with a value of 'URL'. It must also have an xlink:href attribute which contains the URL which points to the file. The URL should be a relative URI which is relative to the location of the METS document itself.

structMap:
requirement: @RELATEDMAT="STRUCT_MAP PRIMARY_REPRESENTATION"
head:
Primary Structural Map

As already described, this profile allows multiple structural maps. However, one of those structural maps must have a TYPE attribute with a value of 'PRIMARY_STRUCTMAP'. Essentially all this moniker signifies is that this structMap is considered by the person who created this METS document or by a later custodian of the file to be the best one for representing the intellectual entity. This is a subjective judgment which may change over time, so the designation may be moved to different structMap elements during the life of the package. This could be a physical, logical, or some other type of structure. For practical purposes, a processing system which requires a structMap which represents the object should choose this structMap as the starting point for processing, unless there is some other alternate structMap which better meets its requirements.

To avoid orphaned files, the primary structMap should reference each file or stream contained in the fileSec.

The primary structural map is where the PRIMARY_REPRESENTATION technical metadata is referenced. The ADMID attribute of the first div child of the primary structural map must reference the techMD element which contains the technical metadata for the PRIMARY_REPRESENTATION.

The primary structural map is also where the PRIMARY_DMDSEC descriptive metadata is referenced. The DMDID attribute of the first div child of the primary structural map must reference the dmdSec element which contains the primary MODS metadata.

If a structLink section is used to represent links between div elements then an xlink:label attribute must be present so that it can be used in the xlink:from and xlink:to attributes of the smLink element. Even though the xlink:label attribute is not an ID-type, it must still follow some of the rules for attributes with a type of ID, namely each xlink:label value must be unique within the METS document.

requirement: @ID="ADMID_STRUCT_MAP"
head:
Administrative Metadata for Structural Maps

All structMap elements should reference via the ADMID attribute of their first div child, a techMD element containing a PREMIS object element. The referenced PREMIS object element must have an objectCategory of REPRESENTATION. This PREMIS object should include an environment element with enough information for a human to determine the suitability of a particular structural map for a given purpose.

All structMap elements should also reference, via the ADMID attribute of their first div child, a digiprovMD element containing a PREMIS event element. The referenced PREMIS event element should have an eventType of either STRUCTMAP_CREATION, STRUCTMAP_TRANSFORMATION, or STRUCTMAP_MODIFICATION. The event should describe who created or transformed the structMap via a referenced linkingAgentIdentifier. The eventDetail should provide some detail about the creation or transformation process such as the type of mapping used for the transformation or other details.

requirement:
head:
Referencing the Primary and Alternate Descriptive Metadata

The first div of each structMap must have a DMDID attribute that references all the primary and alternate dmdSec elements. Remember that the primary and alternate descriptive metadata describes the entire intellectual object represented by the METS document.

requirement:
head:
Referencing Files from the File Section from the Structural Map

Files and bitstreams must be referenced from the structMap via the fptr element. The fptr element must have a FILEID attribute that references the file or bitstream in the file section.

structLink:
requirement:
head:
General Requirements

The structLink element is optional in this profile, and systems which process files conformant to this profile may ignore this element. However, any structLink elements must be preserved during any operations performed on the files, such as transformations, submissions, disseminations, or archiving.

Even though it is optional and may be ignored by processors, if a structLink element is present it is considered an extension to a given structMap. In other words, a single structLink must be associated with a single structMap: all of the xlink:from and xlink:to attributes contained in a structLink must refer back to xlink:label attributes in the same structMap. However, a given structMap may have multiple associated structLink elements. The many-to-one mapping of structLink elements to a structMap element allows any metadata that is associated with the structMap to also apply to the structLink. In other words the combination of the structMap and structLink make up one representation of the intellectual entity, and thus technical or provenance metadata associated to the structMap, via the root div element, apply equally to the associated structLink elements.

Because structLink elements are closely tied to structMap elements, transformations to structural maps can impact structural map links. It is expected that systems which are performing significant transformations to structural maps, such as flattening complex structures for ingest into repositories that only support flat structures, will simply ignore structural map links when creating these derivative structural maps.

behaviorSec:
requirement:
head:
General Requirements

The current profile is primarily concerned with the preservation of files and bitstreams which are required for specific (mostly static) representations of intellectual entities, and not with preserving any complex behaviors that are associated with those representations. Therefore, the behaviorSec element is optional in this profile, and systems which process files conformant to this profile may ignore this element. However, any behaviorSec elements should be preserved during any operations performed on the files, such as transformations, submissions, disseminations, or archiving, but this is not guaranteed by this profile.

requirement: @RELATEDMAT="ADMID_STRUCT_MAP"
head:
Administrative Metadata for Behaviors

Even though the behaviorSec element is optional, this profile considers behaviors to be part of the representation of the intellectual entity. Therefore, in general, behavior elements may be linked to PREMIS administrative metadata similar to Administrative Metadata for Structural Maps. However, at this point systems processing METS files conformant to this profile may ignore these metadata, but they should preserve them in the file.

Administrative Metadata for Structural Maps All structMap elements should reference via the ADMID attribute of their first div child, a techMD element containing a PREMIS object element. The referenced PREMIS object element must have an objectCategory of REPRESENTATION. This PREMIS object should include an environment element with enough information for a human to determine the suitability of a particular structural map for a given purpose. All structMap elements should also reference, via the ADMID attribute of their first div child, a digiprovMD element containing a PREMIS event element. The referenced PREMIS event element should have an eventType of either STRUCTMAP_CREATION, STRUCTMAP_TRANSFORMATION, or STRUCTMAP_MODIFICATION. The event should describe who created or transformed the structMap via a referenced linkingAgentIdentifier. The eventDetail should provide some detail about the creation or transformation process such as the type of mapping used for the transformation or other details.
multiSection:
requirement:
head:
Summary of Possible Linkages Between Sections

The following requirements will summarize what types of IDREFS to ID linkages are described in this profile both to and from a particular element. Linkages which are not explicitly described here are allowed, but systems conforming to this profile may ignore those linkages, and in some cases these linkages may be removed during transformations of the METS file. A notation based on the XPath language will be used along with the following arrows to signify cardinality:

     <- or -> signifies a zero to one link (an optional link to up to one destination element)

     <<- or ->> signifies a zero to many link (an optional link to many destination elements)

     <= or => signifies a one to one link (a required link to exactly one destination element)

     <<= or =>> signifies a one to many link (a required link to one or more destination elements)

requirement:
head:
Descriptive Metadata

     dmdSec[@STATUS='PRIMARY_DMDSEC' or @STATUS='ALTERNATE_DMDSEC'][email protected] =>> digiprovMD[.//premis:event][email protected]

     dmdSec[@STATUS='PRIMARY_DMDSEC'][email protected] <= [email protected]

     dmdSec[@STATUS='PRIMARY_DMDSEC']//mods:relatedItem[@type="constituent"][email protected] <- [email protected]

     dmdSec[@STATUS='ALTERNATE_DMDSEC'][email protected] <<= [email protected]

     dmdSec[@STATUS!='ALTERNATE_DMDSEC' and @STATUS!='PRIMARY_DMDSEC' ][email protected] <<- [email protected]

requirement:
head:
Administrative Metadata
head:
  Technical Metadata
head:
    Files and Bitstreams

     techMD[.//premis:objectCategory = 'FILE' ][email protected] <= [email protected]

     techMD[.//premis:objectCategory = 'BITSTREAM' ][email protected] <= [email protected]

     techMD[.//textMD][email protected] <- file[starts-with(@MIMETYPE,'text/')][email protected]

     techMD[.//mix:mix][email protected] <- file[starts-with(@MIMETYPE,'image/')][email protected]

     techMD[.//audiomd:*][email protected] <- file[starts-with(@MIMETYPE,'audio/')][email protected]

     techMD[.//videomd:*][email protected] <- file[starts-with(@MIMETYPE,'video/')][email protected]

     techMD[.//premis:creatingApplication and premis:software][email protected] <= file[starts-with(@MIMETYPE,'application/')][email protected]

     techMD[.//jhove:jhove][email protected] <- [email protected]

head:
    Representations

     techMD[@STATUS='PRIMARY_REPRESENTATION' and .//premis:objectCategory = 'REPRESENTATION' ][email protected] <= structMap[@TYPE='PRIMARY_STRUCTMAP'][email protected]

     techMD[.//premis:objectCategory = 'REPRESENTATION' ][email protected] <- [email protected]

     techMD[.//premis:objectCategory = 'REPRESENTATION' ][email protected] <- [email protected]

head:
  Source

     [email protected] <<- [email protected]

head:
  Rights

     rightsMD[.//premis:rights][email protected] <<- [email protected]

     rightsMD[.//premis:agent][email protected] <- rightsMD//premis:rights//grantingAgent [email protected]

head:
  Digital Provenance

     digiprovMD[.//premis:event][email protected] <<= dmdSec[@STATUS='PRIMARY_DMDSEC'][email protected]

     digiprovMD[.//premis:event][email protected] <<= dmdSec[@STATUS='ALTERNATE_DMDSEC'][email protected]

     digiprovMD[.//premis:event][email protected] <<- [email protected]

     digiprovMD[.//premis:event][email protected] <<- [email protected]

     digiprovMD[.//premis:event][email protected] <<- [email protected]

     digiprovMD[.//premis:agent][email protected] <-digiprovMD//premis:[email protected]

requirement:
head:
Content Files

     [email protected] => techMD[.//premis:objectCategory = 'FILE' ][email protected]

     [email protected] => techMD[.//premis:objectCategory = 'BITSTREAM' ][email protected]

     file[starts-with(@MIMETYPE,'text/')][email protected] -> techMD[.//textMD][email protected]

     file[starts-with(@MIMETYPE,'image/')][email protected] -> techMD[.//mix:mix][email protected]

     file[starts-with(@MIMETYPE,'audio/')][email protected] -> techMD[.//audiomd:*][email protected]

     file[starts-with(@MIMETYPE,'video/')][email protected] -> techMD[.//videomd:*][email protected]

     file[starts-with(@MIMETYPE,'application/')][email protected] => techMD[.//premis:creatingApplication and .//premis:software][email protected]

     [email protected] -> techMD[.//jhove:jhove][email protected]

     [email protected] <= [email protected]

     [email protected] <= [email protected]

requirement:
head:
Structural Maps

     [email protected] => dmdSec[@STATUS='PRIMARY_DMDSEC'][email protected]

     [email protected] -> dmdSec[@STATUS='PRIMARY_DMDSEC']//mods:relatedItem[@type="constituent"][email protected]

     [email protected] =>> dmdSec[@STATUS='ALTERNATE_DMDSEC'][email protected]

     [email protected] ->> dmdSec[@STATUS!='ALTERNATE_DMDSEC' and @STATUS!='PRIMARY_DMDSEC' ][email protected]

     structMap[@TYPE='PRIMARY_STRUCTMAP'][email protected] => techMD[@STATUS='PRIMARY_REPRESENTATION' and .//premis:objectCategory = 'REPRESENTATION' ][email protected]

     [email protected] -> techMD[.//premis:objectCategory = 'REPRESENTATION' ][email protected]

     [email protected] ->> digiprovMD[.//premis:event][email protected]

     [email protected] => [email protected]

     [email protected] => [email protected]

     [email protected]:label <<- [email protected]:from

     [email protected]:label <<- [email protected]:to

requirement:
head:
Structural Map Links

     [email protected]:from => [email protected]:label

     [email protected]:to => [email protected]:label

technical_requirements:
content_files:
requirement:
head:
General

This profile can support any type of content file. However, this profile does assume that referenced or embedded content files have been normalized to their most primitive composition level, specifically content files must not be compressed or encrypted. This is equivalent to a PREMIS composition level of zero. Also, it is assumes that content files are accessible directly from the URI where they reside without needing to be extracted from any intermediate packaging file, such as a ZIP or TAR archive. Note that an intermediate packaging format such as ZIP or TAR may be used for conveniently transporting a complete package of files including the METS file itself, but any references to files in the METS must refer to the files after the package has been decomposed into its parts.

behavior_files:
requirement:
head:
General

This profile has no requirements for behavior files.

metadata_files:
requirement:
head:
General

All metadata referenced in this profile must be well-formed XML and must validate to the relevant XML Schema.

requirement:
head:
MODS

The MODS descriptive metadata must conform to the Digital Library Federation / Aquifer Implementation Guidelines for Shareable MODS Records. [http://www.diglib.org/aquifer/dlfmodsimplementationguidelines_finalnov2006.pdf] All requirements in the Aquifer guidelines listed as "REQUIRED" or "REQUIRED IF APPLICABLE" must be adhered to by METS files conformant to this profile.

tool:
name:
ECHODEP Hub and Spoke Interoperability Scripts
agency:
University of Illinois at Urbana-Champaign

  Top of Page Top of Page
 
  The Library of Congress >> Standards
  July 1, 2011

Legal | External Link Disclaimer

Contact Us