NISO has released KBART: Knowledge Bases and Related Tools (NISO RP-9-2010).
Here's an excerpt from the announcement:
UKSG and NISO are pleased to announce the first report by the KBART (Knowledge Bases and Related Tools) Working Group, a joint initiative that is exploring data problems within the OpenURL supply chain. The KBART Recommended Practice (NISO RP-9-2010) contains practical recommendations for the timely exchange of accurate metadata between content providers and knowledge base developers.
The KBART Recommended Practice, a report from Phase I of the KBART project, provides all parties in the information supply chain with straightforward guidance about the role of metadata within the OpenURL linking standard, and recommends data formatting and exchange guidelines for publishers, aggregators, agents, technology vendors, and librarians to adhere to when exchanging information about their respective content holdings.