|First Indicator||Second Indicator|
# - Undefined
|162/462/562 - Undefined
# - Undefined
762 - Thesaurus
0 - Library of Congress Subject Headings
1 - LC subject headings for children's literature
2 - Medical Subject Headings
3 - National Agricultural Library subject authority file
4 - Source not specified
5 - Canadian Subject Headings
6 - Répertoire de vedettes-matière
7 - Source specified in subfield $2
Main term portion
Tracing and linking subfields
Content designators identify the elements occurring in medium of performance term headings constructed according to generally accepted thesaurus-building conventions (e.g., Library of Congress Medium of Performance Thesaurus). Medium of performance terms designate instruments, voices, ensembles, and other media that can be used to perform musical compositions.
Only generally-applicable content designators are described in full in this section. A small number of content designators with field-specific instructions are described in the Tracings and References-General Information section (for field 462 and 562) and the 7XX Heading Linking Entries-General Information section (for field 762).
In fields 162, 462, and 562, the second indicator position is undefined and contains a blank (#). For field 762, the second indicator position contains one of the values described in the 7XX Heading Linking Entries-General Information section.
$a - Medium of performance term
May consist of more than one word
$i - Relationship information [462/562]
Designation of a relationship of the entity in a 462 or 562 field to the 1XX entity in the record or a textual reference instruction phrase than those that may be system-generated from the field tag or from the codes defined for subfield $w (Control subfield). Subfield $i is appropriate only in fields 462 and 562. Guidelines for using subfield $i are provided in the Tracings and References-General Information section.
$w - Control subfield [462/562/762]
Codes in one or more character positions defined to control the display of information and specify relationships, restrictions, and status. Subfield $w is appropriate only in field 462, 562, and 762. Character position definitions and guidelines for applying the codes defined for subfield $w in field 462 and 562 are provided in the Tracings and References-General Information section. Character position definitions and guidelines for field 762 are provided in the 7XX Heading Linking Entries-General Information section.
$0 - Authority record control number or standard number [562/762]
$2 - Source of heading or term 
Code that identifies the source of a heading or term when the second indicator position contains value 7. Subfield $2 is appropriate only in field 762. Guidelines for applying subfield $2 are provided in the 7XX Heading Linking Entries—General Information section.
$4 - Relationship code [462/562]
Contains in coded form the designation of a relationship of the entity in a 462 or 562 field to the 1XX entity in the record. Guidelines for using subfield $4 are provided in the Tracings and References-General Information section.
$5 - Institution to which field applies [462/562/762]
$6 - Linkage
$8 - Field link and sequence number
Punctuation - An X62 field does not end with a mark of punctuation unless the field ends with an abbreviation, initial/letter, open date, or other data that ends with in a mark of punctuation.
Spacing - No spaces are used in initialisms, acronyms, or abbreviations.