Introduction: Using URLs as identifiers has caused no end of problems. E.g., in DFDL we have http://www.ogf.org/dfdl/dfdl-1.0/ as an identifier. W3C has http://www.w3.org/2001/XMLSchema and others. W3C has badly regretted establishing this convention, as they have farms of servers that do nothing but quickly return 404 errors to save network-aware applications the network-timeout delay that would otherwise occur. There are parties interested in exploiting DFDL who want DFDL schemas to NOT contain network URLs because it simply creates a concern about network access whenever a DFDL schema is inspected/used. Pre-Proposal: The new way to do this is with URNs which would look roughly like this: urn:ogf:dfdl:standard:dfdl-1.0. The whole point is that some other mechanism is used to establish correspondences between these and any resources in file systems, networks, or built-in to implementations. One such mechanism is called XML Catalog. The point is that it is a name in a managed namespace which cannot be confused with a network protocol URL. OGF is already establishing urn:ogf, and an ogf subgroup has already proposed urn:ogf:network for network resources. DFDL schemas aren't network resources so we don't want to be a substructure underneath network. Some other mechanism is used to establish correspondences between these and any resources in file systems, networks, or built-in to implementations. One such mechanism is called XML Catalog. Summary: An action item should be to specify DFDL urn, submit to OGF as a proposed namespace, and then produce errata/spec changes to specify its use. This requires a small design activity to specify a scheme for the sub-structure of the DFDL URNs (i.e., scheme for the stuff after urn:ogf:dfdl:...) where we want standard identifiers for versions of the standard, but we probably also want a few other things (e.g., I would like a space for implementations to identify themselves, i.e., an implementation-specific sub-area within our URNs.) Our existing URLs can be compatible (deprecated) practice vs the preferred URNs. -- Mike Beckerle | OGF DFDL WG Co-Chair Tel: 781-330-0412