PREMIS Data Dictionary for Preservation Metadata (version 2.0): Errata and Proposed Changes

This document records corrections and proposed changes to version 2.0 of the PREMIS Data Dictionary for Preservation Metadata (PDF:1.1MB/184pp.) and PREMIS schemas.
[Note: To view PDF documents, a free viewer is available for download from Adobe Acrobat.]

Errata
The following details mistakes or omissions that will be corrected in the next version.

Add linking semantic units from Agent Entity to Events and Rights:
- linkingEventIdentifier (linkingEventIdentifierType and linkingEventIdentifierValue)
- linkingRightsStatementIdentifier (linkingRightsStatementIdentifierType and linkingRightsStatementIdentifierValue)
Clarify that the linking semantic units are mandatory in the sense that a repository needs to know the information, but are defined as optional because PREMIS does not specify in which direction the linkage should be.
Correct the "Rationale" for objectCharacteristicsExtension to say "There may be a need to extend PREMIS defined units." Replacing is not allowed.
Make storage optional, since it is not useful for exchange (corrected in schema)
Add "Not applicable" for representation under 1.9.1.5 signatureValidationRules
Add "Not applicable for representation under 1.9.2 signatureInformationExtension
Provide common definitions for linkingAgentIdentifier under event and rightsStatement:
- Make linkingAgentRole optional and repeatable for rightsStatement instead of mandatory and not repeatable
- Add attributes LinkAgentXmlID and xlink:simpleLink for rightsStatement
Provide common definitions for linkingObjectIdentifier under event and rightsStatement:
- Add linkingObjectRole (optional, repeatable) to rightsStatement
- Add attributes LinkObjectXmlID and xlink:simpleLink for rightsStatement
Correct repeatability of format in schema (now is maxOccurs=1, should be maxOccurs="unbounded")
Correct Usage notes for 1.8.1 environmentCharacteristic from "recommended = an environment preferred for optional rendering" to: "recommended = an environment preferred for optimal rendering"

Approved Data Dictionary and/or Schema changes
The following details changes approved by the PREMIS Editorial Committee.

Add agentNote and agentExtension to the agent entity (September 15, 2010)

Define additional elements and attributes for all extension elements to create a structure similar to that used with METS extension schemas (e.g. add element to indicate whether the metadata is a reference or wrapped within the metadata section; add indication of metadata type, etc.). All extension elements will be repeatable.

Proposed Data Dictionary and Schema changes
The following details suggested changes for the next version. Decisions have not yet been made on the proposals.

Consider relationshipType for dependency relationships that are not structural or derivative, but necessary for understanding (not rendering) the object. (Dependency relationships are only used under environment.)
Define intellectual entities as another level of object and supply semantic units for them
Define a certainty semantic unit/attribute to express how certain a value or group of values are. This would be most useful on the format elements, where it has not been possible to get a definitive identification of the format of a file object.