Appendix E: Revision History

REC-GML2 (Recommendation, 2001-02-20):

• extensive restructuring of content

• fixed usage of 'type' attribute in xlinks utility schema

• the XLink schema is now normative

• feature collections can now be empty (per OGC Abstract Specification)

• renamed FeatureMemberType and GeometryMemberType to FeatureAssociationType and GeometryAssociationType, respectively

• updated UML diagrams

• added UML diagrams for the 'Cambridge' and 'Schools' examples

• expanded discussion about profiles and application frameworks (sec. 7)

PR-GML2 (Proposed Recommendation, 2001-01-15):

• Moved discussion of XLink attributes to section 4.4 and deleted the GeoLinks schema

• Removed material on temporal data (sec. 6) to a separate GML Module

• purged RDF remnants

• changed the names of identifying attributes ('fid' for features, 'gid' for geometry elements)

• added gml:AssociationType to support pointers to remote feature properties

• miscellaneous editorial changes

CR-GML2 (Candidate Recommendation, 2000-12-22):

• changed srsName attribute to type="uriReference"

• the featureMember element and all basic geometric properties can also function as pointers to remote resources (i.e. as simple-type XLink elements)

• added a brief introduction to section 5 that clarifies the different ways GML can be used to express associations (i.e. containment vs. linking)

• added an example to section 5.4 demonstrating the use of a linkbase to store instances of feature relationships (Listings 5.7 - 5.9)

• inserted comments concerning feature identification (sec. 4.2)

• miscellaneous corrections: invalid feature identifiers; invalid xlink:role attributes

• coordinate strings may now contain 1D, 2D, or 3D tuples

• added a description of the Feature Filter design pattern (sec. 4.4.6)

• removed the gml:label attribute from the GeoLinks schema