Abstract Information Types

In today's TechComm SC call we discussed the idea of an abstract layer for DITA Information Types. I mentioned that the BusDocs SC had studied this same issue and released a report in 2009 addressing a proposed abstract layer.  Please find our published report in the BusDocs document library or at  https://www.oasis-open.org/apps/org/workgroup/dita-busdocs/download.php/37193/Simplifying%20Information%20Types%20in%20DITA.pdf
Please let me know if I can answer any of your questions about this document.  Cheers, Rob Hanna  Senior Information Architect Innovatia, Inc.