The attribute gml:id supports provision of a handle for the XML element representing a GML Object. Its use is mandatory for all GML objects. It is of XML type ID, so is constrained to be unique in the XML document within which it occurs.
The "srsDimension" is the length of coordinate sequence (the number of entries in the list). This dimension is specified by the coordinate reference system.
In general this reference points to a CRS instance of gml:CoordinateReferenceSystemType (see coordinateReferenceSystems.xsd). For well known references it is not required that the CRS description exists at the location the URI points to.
<complexType name="LineStringCurveType"><annotation><documentation>A Simplified version of gml:CurveType with only LineStringSegments.</documentation></annotation><complexContent><extension base="metobj:SelfContainedAbstractCurveType"><sequence><element ref="metobj:lineStringSegments"><annotation><documentation>This element encapsulates the segments of the curve.</documentation></annotation></element></sequence></extension></complexContent></complexType>