Recommendations towards “Updating the Qualified Dublin Core registry in DSpace to the latest standards of the DCMI,” a priority identified in the October 2011 community survey on improving metadata support. It also seeks to comply with the proposal to Standardize the Default Namespace. Discussion of this issue thus far is stored as a DCAT Discussion Forum topic, "Updating the Qualified Dublin Core registry in DSpace."

Recommendation (tentative, pending further community input):

• Update current “DCMI Terms” metadata registry to QDC
• Add DCTERMS as new, parallel metadata registry
• Lockdown registries, offering migratory tools to pull out local customizations and push into new local schema. Make it possible but not easy to delete or edit elements in QDC and DCTERMS registries. Continue to enable the addition of qualifiers in the QDC registry

Main goal of these recommendations:

• Take steps toward ultimate goal of full compliance with DCTERMS, thus ensuring compliance with current standards endorsed by DC and linked data capabilities. By bringing the existing “DCMI” registry into QDC compliance, we also provide an intermediate migration step, enabling repositories to meet compliance with QDC upon upgrade, which will ease the transition to DCTERMS.
• By locking down registries, ensure compliance with QDC and DCTERMS standards but provide tools to allow customizations not compliant with QDC/DCTERMS to persist in local schema. 

Outstanding issues for committers and community:

• Is it possible to ultimately implement DCTERMS with full functionality? What changes to the data model will be necessary?
• If both QDC and DCTERMS are included, which will be considered the default? Is this projected to change?
• How will this proposal integrate with other suggested changes to DSpace metadata, including Proposal for Metadata Enhancement? How might it affect integration with Fedora? How might it affect other desired changes to metadata in DSpace, including implementing functional structured metadata such as MODS, METS, and PREMIS?
• What challenges will this proposal present—or solve—for harvesting?
• To enable repositories to migrate existing metadata to QDC and DCTERMS registries, we will need to develop robust tools for repositories to deploy. One outstanding issue is the design and development of these tools.  

Relevant JIRA tickets:

(please add any JIRA tickets that could be affected by this proposal!)

DS-125: Date type can't be repeatable in the submission

DS-202: Metadata Generator Plugin

• Not sure whether this is related. But I assume if DCMI requires some properties to be unique (for example identifiers), I guess you would need a generator to ensure unique identifiers get generated.  

DS-433: Update DublinCore Registry to Implement latest DC Standards

DS-716: Add an administrative metadata schema to DSpace

DS-800: Manage visibility of metadata fields as field attribute rather than in dspace.cfg 

DS-805: QDC schema registry needs to be brought into conformity with the current DCMI standards

DS-815: DCDate throws NullPointerException with mangled dates

DS-1134: Multilingual metadata for communities/collections

DS-1420: Exception handling for deleting a metadata field

Areas/processes that will be affected by registry update:

What areas and processes will be affected by these shifts? Is there any documentation of what features in DSpace are making use of certain fields? Where will the code be affected? Where are metadata elements hardcoded?

(pulled from September 4, 2012, DCAT discussion)

• Any processes that create new metadata in DSpace:
  
  • submission forms
  • spreadsheet importer
  • command line import
  • SWORD
  • built-in OAI Harvester

• Any process that displays metadata in the web used interface:
  
  • item pages
  • search, browse, DSpace discovery

• Any process that delivers the metadata (potentially via crosswalks) to other applications:
  • OAI server
  • REST API