A reference from a sampling feature to a sampling feature group it is a member of.This is membership, never containment, which is why it is separate fromdiggs:samplingFeatureRef: it means only that the feature is interpreted jointly withthe other members of the group, is always optional, and places no spatial orstructural obligation on either end. The member cites the group; seediggs:AbstractProjectScopedGroup. A feature may belong to more than one group; forexample a borehole can be a member of a borehole/CPT pair and of a widerinvestigation-phase group. Given by reference only.
The gml:identifier value of the referenced feature, as a fully qualifiedvalue. It gives an alternative to the gml:id in xlink:href for findingthe referenced feature, mainly to reference a feature by a globallyunique identifier and where naming conflicts occur with gml:id whenaccessing data in external files.
<element name="samplingFeatureGroupRef" type="diggs:FeatureReferenceType"><annotation><appinfo source="urn:x-gml:targetElement">diggs:AbstractSamplingFeatureGroup</appinfo><documentation>A reference from a sampling feature to a sampling feature group it is a member of. This is membership, never containment, which is why it is separate from diggs:samplingFeatureRef: it means only that the feature is interpreted jointly with the other members of the group, is always optional, and places no spatial or structural obligation on either end. The member cites the group; see diggs:AbstractProjectScopedGroup. A feature may belong to more than one group; for example a borehole can be a member of a borehole/CPT pair and of a wider investigation-phase group. Given by reference only.</documentation></annotation></element>
