NISO has released a draft of NISO RP-20-201x, Demand-Driven Acquisition of Monographs for comment.
Here's an excerpt from the announcement:
The National Information Standards Organization (NISO) is seeking comments on the draft recommended practice Demand-Driven Acquisition of Monographs (NISO RP-20-201x). Launched in June 2012, the NISO Demand Driven Acquisition (DDA) Working Group was charged with developing a flexible model for DDA (also referred to as patron-driven acquisition) that works for publishers, vendors, aggregators, and libraries. The draft Recommended Practice discusses and makes recommendations about key aspects of DDA, goals and objectives of a DDA program, choosing parameters of the program, profiling options, managing MARC records for DDA, removing materials from the consideration pool, assessment of the program, providing long-term access to un-owned content, consortial considerations for DDA, and public library DDA.