Rome, Aug. 30, 2010

 Current status of vocabularies  Reorganization of CGI workgroups  Vocabulary resource management  Change URI scheme from URN to http URI

Subversion repository

Metadata Preferred label (en, others) Text definition (en) Asserted hierarchy

 Auscope  BRGM

 New vocab group being organized  Merge with Multilingual thesaurus group  Develop statement of work  Meeting planned this fall to formally organize/kick off

 Move to repository to GeoSciML.org  Authorities for OGE vocabularies (CGI or ?)  New vocabulary requirements for v3 documents  Formal decisions and policies to be developed by new workgroup

For CGI resources

 Identify information and non-information resources  expected to be dereferenceable using the existing DNS system on the Internet

 HTTP URI's are URI's, so may appear as the value of in a GML-conformant document  They are persistent  May identify offline- as well as online-resources  Implies immediate resolvability -- a Good Thing in most circumstances  Structure is "facetted".  Enables more flexible rules for identifier governance.  Composed of slash-delimited alphanumeric fields.  Allows some explicit semantics to be visible  may imply resource-type, ownership, even value  often useful during system development.  OGC has adopted in its service architecture (with apologies to Simon Cox

 four distinct but related resources that we might like to identify using an HTTP URI (Booth)  Identifier label: actual string (info)  A concept or physical entity (non info)  Web Location: the information resource that is produced by an HTTP GET request using that URI (non information). There is no guarantee that the same web location will GET the same resource when it is recalled  A particular document instance (info)

 Identifiable and transparent to people. Branding: trust, advertising; evident what is identified  Memorable  Keyboard compatible  Usable, reliable, documented  Distributed (delegate support for the transfer of naming authority)  Stable, cost effective  Portable-- change dereferencing host system without reengineering identifiers

 303 code response redirect is invisible to a human user  Compilicates relocation of the dereferencing host for legacy URIs.  Suggestion is to explicitly distinguish the dereferencing host from the name authority,  these may be decoupled.  Content negotiation and URL redirection invisible to the user violate requirement for URI transparency

 “urn” “:”  “cgi” “:”  CGIResource “:”  ResourceSpecificString  protocol  Name authority  Resource type  Resource ID

 “http” “://”  host “/”  “cgi-uri” “/”  Authority “/”  cgi resource “/”  resource specific identifier  Protocol  Host authority  URI scheme ID  Name authority  Resource type  Resource ID

 " "//"  Host “/”  URIscheme “/”  nameAuthority “/”  resourcePath “/”  resourceSpecificString “/”  [representationPart]  protocol  Dereferencing service  URI scheme ID  Name Authority ID  Resource type  Resoure ID  Representation ID  Representation instance ID?

 Stem part with host name, authority, resource type path part, opaque resource- specific part.  E.g

 Proposal to reverse the CGIResource/Authority pair to Authority/CGIResource  How are particular representations identified?  file extensions ('.rdf', '.html').  content negotiation  Is host part considered part of the identifier string.  Underscores ‘_’ or hyphens ‘-’ in http URIs  All characters  lower-case  CamelCase

 Rdf  Html  GeoSciML fragment  Defined based on resource type