Premis or Preservation Metadata: Implementation Strategies international working group was established by OCLC and RLG in 2003. Its final report, Data dictionary for preservation metadata, was published in May 2005, defines and describes an implementable set of core preservation metadata with broad applicability to digital preservation repositories. This report is intended to put the Data Dictionary into context, explain the underlying assumptions and data model, and provide additional information about the meaning and use of semantic units defined in the Data Dictionary. The Premis maintenance activity is undertaken by the Library of Congress.
As part of the implementation of the Vital digital asset management system at the National Library it has been decided to use the Premis data dictionary to identifyu preservation metadata elemetns and to encode those metadata using the Premis XML schemas for including in the NLW METS containter.
Premis enumerates four classes of preservation metadata entities.