Relation to application schema

Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. 223  include all mandatory particles subelements and attributes of the parent element in GML.  include no particle that is not in the parent element in GML.  have the same default values for attributes as the parent element in GML.  have a parallel substitution group hierarchy for named elements in both schemas. Global types in a GML profile shall:  share the same name and namespace of a parent type in GML.  include all mandatory particles subelements and attributes of the parent type in GML.  include no particle that is not in the parent type in GML.  have the same default values for attributes as the parent type in GML.  have a parallel derivation tree for named types in both schemas. Instance documents of a profile shall be valid against the full GML schema. Using the ―copy and delete‖ metaphor described above, our mythic developer may:  delete global elements and global types.  delete optional subelements from any types or elements.  make optional subelements or attributes mandatory in any type or element if a default value exists, it shall be eliminated or the schema validation will report an error  default values are only valid for optional particles.  restrict cardinality of any particle. None of the above will affect the validity of a document that is designed against the profile, but tested against the full GML schema. Our mythic developer may not:  delete mandatory subelements from any types or elements.  make mandatory particles optional.  relax cardinality restrictions of any particle.  add or change a default or fixed value. The last item is a bit subtler than the others are. Documents valid under the profile would still be valid under the full GML schema, but the interpretation of those documents would change. For example, if a profile specified a default coordinate reference system to be UTM, and the full schema specified a WGS 84 geodesic latitude, longitude as the default CRS, then the interpretation of the file would change when moving from the profile to the full schema.