The number and variety of data elements in the EIDR Content ID Registry can seem daunting, but only a small number of them are actually required for every record. Most of them exist to address particular use cases or only apply to certain types of records. In general, the EIDR data elements are grouped into four categories:
- Required – Must be present in every record, either provided directly or inherited from a parent record.
- Conditionally Required – Required under certain circumstances.
- Optional, but Highly Recommended – Not required, but encouraged due to their high value in discovery and de-duplication.
- Optional, and Only Applicable in Select Use Cases – Not required.
This document addresses the Required, Conditionally Required, and Optional but Recommended data elements. Information about the truly optional fields is in EIDR’s Data Fields Reference Guide and Best Practices for Creating Abstraction Records.
- Required Data Fields – Abstraction
- Required Data Fields – Series
- Required Data Fields – Season
- Required Data Fields – Episode
- Required Data Fields – Edit
- Required Data Fields – Clip
- Required Data Fields – Manifestation
 The primary determination for data requirements is the record’s Referent Type (Movie, Series, Season, etc.), but for certain Referent Types, that may vary by position in the registration tree (root vs. child record).
 In XML, there are tags, which carry a data payload, and attributes of the tags. We distinguish the two by using an at-symbol (@) for the attributes. When XML tags are nested, one inside another, we focus on those that carry data or have attributes. The nesting information is presented as a slash (/) separated tag list. Information on tags that exist only as containers is in Data Fields Reference.