A reference to a sampling feature. The meaning depends on the type that declares it.Provenance, on observations, measurements, sampling activities, samples andconstruction activities: the sampling feature the data came from, or that theactivity was performed on. Containment, on the installation types(diggs:AbstractLinearInstallationType, diggs:AbstractPlanarInstallationType anddiggs:AbstractPointInstallationType): the host sampling feature the installation wasconstructed within; it is mandatory there. Both point at an antecedent. A type thatneeds to narrow the permitted target beyond diggs:AbstractSamplingFeature does sowith a local annotation on its own element reference, as diggs:RIColumnType does.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="samplingFeatureRef" type="diggs:FeatureReferenceType"><annotation><appinfo source="urn:x-gml:targetElement">diggs:AbstractSamplingFeature</appinfo><documentation>A reference to a sampling feature. The meaning depends on the type that declares it. Provenance, on observations, measurements, sampling activities, samples and construction activities: the sampling feature the data came from, or that the activity was performed on. Containment, on the installation types (diggs:AbstractLinearInstallationType, diggs:AbstractPlanarInstallationType and diggs:AbstractPointInstallationType): the host sampling feature the installation was constructed within; it is mandatory there. Both point at an antecedent. A type that needs to narrow the permitted target beyond diggs:AbstractSamplingFeature does so with a local annotation on its own element reference, as diggs:RIColumnType does. Given by reference only.</documentation></annotation></element>
