EAD Tag Library for Version 1.0

EAD Attributes: Introduction

Attributes are associated with most of the elements contained in EAD. These attributes reflect named properties of an element and may take on different values, depending on the context in which they occur. In order to set one or more attributes, an encoder should include the name of the attribute(s) within the same angle bracket as the start tag, together with the value(s) to which the attribute(s) is/are to be set. That is,

<[tag] [attribute]="[value]">; or; <[tag] [attribute1]="[value1]" [attribute2]="[value2]">
For example:: <unitdate type="inclusive">1937-1992</unitdate>; or; <origination label="Creator:">Kenny, Elizabeth</origination> <unittitle encodinganalog="MARC 245" label="Title:">Elizabeth Kenny Papers</unittitle>

Most attributes are optional and of the type called #IMPLIED. A few attributes are flagged as #REQUIRED or #FIXED.

#IMPLIED The attribute is not required. If no attribute value is specified, the program may imply a value based either on the last specified value or a default value.

#REQUIRED The attribute must be specified within the start tag for the element, e.g.:
<archdesc level="recordgrp">

#FIXED The attribute has only one possible value which is specified by the DTD.

The kind of data an attribute may contain is abbreviated with one of the following standard SGML designations to help the parser validate that the data content of an attribute is acceptable. For example, if an attribute should only be a unique identification name, the attribute data type can be specified as "ID." Most EAD element attributes contain CDATA, which means that any text characters are acceptable.

CDATA: Character data. No SGML markup is recognized where CDATA is allowed, except for the angle bracket that ends the character data string. In other words, no entity references are needed to include characters such as the right angle bracket, which would be interpreted as an SGML action code in #PCDATA.

ENTITY: The name of a group of characters that has been declared elsewhere. For example, the ENTITYREF attribute must contain a valid "entity" expression. When the entity name is stated in an attribute, a body of text or a file can display as part of the encoded document.

ID: Unique identifier. For example, most elements have an ID attribute, so that a unique name can be established for them and used to refer to that specific element among many similarly named elements. The content of the ID attribute is of the type called "id," because the SGML parser can then check that the ID is, in fact, unique.

IDREF: ID reference value; previously entered ID of another element. For example, the <container> element has a PARENT attribute that can only be an "idref," which means it has a reference to a valid ID in another attribute.

IDREFS: List of ID reference values.

NMTOKEN: A name token; a one-word value consisting of letters or numbers that provide a shorthand name for the element. The <colspec> table element has a COLNAME attribute that must be a "nmtoken."

NMTOKENS: List of name tokens.

When the EAD DTD limits attribute values to a few choices, those values are also stated as part of what is known as a closed list. For example, the values of the attribute AUDIENCE are limited to either "external" or "internal." Some attributes are associated with semi-closed lists. Such lists include those values believed to be the most useful in many contexts. Since the DTD creators could not anticipate all occurrences of the attribute, the list permits a user-defined value as well. For example, the <container> element includes many container types in a semi-closed list. Setting the TYPE attribute to "othertype" makes it possible to specify in a separate OTHERTYPE attribute container types such as "super oversize" that are not in the semi-closed list for TYPE. The definitions for some values in the closed and semi-closed lists appear below.

The following is a complete list of all the attributes that occur in EAD, and some discussion of how they may be used. Attributes that are used for linking and for tabular display are defined in separate lists that follow the General Attributes list.

EAD Attributes Menu
Introduction	General Attributes	Linking Attributes	Tabular Display Attributes

Table of Contents

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Principles Overview of
EAD Structure Tag Library
Conventions EAD Attributes EAD Elements
by Tag Name Index of
EAD Element Names

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#IMPLIED	The attribute is not required. If no attribute value is specified, the program may imply a value based either on the last specified value or a default value.
#REQUIRED	The attribute must be specified within the start tag for the element, e.g.: <archdesc level="recordgrp">
#FIXED	The attribute has only one possible value which is specified by the DTD.

CDATA:	Character data. No SGML markup is recognized where CDATA is allowed, except for the angle bracket that ends the character data string. In other words, no entity references are needed to include characters such as the right angle bracket, which would be interpreted as an SGML action code in #PCDATA.
ENTITY:	The name of a group of characters that has been declared elsewhere. For example, the ENTITYREF attribute must contain a valid "entity" expression. When the entity name is stated in an attribute, a body of text or a file can display as part of the encoded document.
ID:	Unique identifier. For example, most elements have an ID attribute, so that a unique name can be established for them and used to refer to that specific element among many similarly named elements. The content of the ID attribute is of the type called "id," because the SGML parser can then check that the ID is, in fact, unique.
IDREF:	ID reference value; previously entered ID of another element. For example, the <container> element has a PARENT attribute that can only be an "idref," which means it has a reference to a valid ID in another attribute.
IDREFS:	List of ID reference values.
NMTOKEN:	A name token; a one-word value consisting of letters or numbers that provide a shorthand name for the element. The <colspec> table element has a COLNAME attribute that must be a "nmtoken."
NMTOKENS:	List of name tokens.

Table of Contents
Home Page	Acknowledgments	Introduction	EAD Design Principles	Overview of EAD Structure	Tag Library Conventions	EAD Attributes	EAD Elements by Tag Name	Index of EAD Element Names