Music Library Association Best Practices for content type

Routinely record the element in bibliographic records for primary content of the resource and for substantial accompanying material, that is, material for which the extent is explicitly recorded. Record the element for accompanying material that is described only in a note if deemed useful for identification or selection.

In MARC: Record as a structured description using field 336 subfield $a. Additionally, for accompanying material: Record as an identifier using field 006 if content type differs from the primary content of the resource.

For resources issued with supplementary content, select the most appropriate option based on cataloger's judgment and the following guidelines:

• Books or scores issued with audio/video carriers: record the element for the audio or video content.
• Audio/video carriers with a substantial accompanying volume of text (insert, booklet, etc.): record the element for the textual content.
• Scores with significant textual content (critical commentary, libretto, preface, etc.): record the element for the textual content; however, do not record the element merely to represent words which underlay notated music.

In MARC: For resources with multiple carrier types, specify the carrier to which the element refers in field 336 subfield $3 if deemed useful for identification or access.

In MARC: If recording a term from the recommended vocabulary encoding scheme, indicate the source of information using the $2 code rdacontent.