Metadata harvesting: Para.4.10 Manual on WIS (No. 1060)
4.10 WIS-TECHSPEC-9: CONSOLIDATED VIEW OF DISTRIBUTED DAR METADATA (WIS DISCOVERY METADATA) CATALOGUES
4.10.1 GISCs should exchange metadata catalogue updates using version 2 of the Open Archives Initiative–Protocol for Metadata Harvesting (OAI-PMH).
4.10.2 The exchange of metadata catalogue updates should satisfy the requirement for distributed instances of DAR metadata (WIS discovery metadata) not to diverge in content by more than one day. A mechanism for rapid update on an emergency basis should also be provided.
4.10.3 See also 3.5.6 (Discovery, access and retrieval).