A feature can link to other features via a feature link property in the type specific data of the feature or of an observation of a feature. The feature link property defines via validation rules which feature types can be linked from this specific property. The feature or observation that stores the reference to another feature is the the source of this feature link relation, the linked feature is the destination of the feature link relation.

The system can determine all features that are linked to a specific feature through a feature link relation, i.e. all features that are destination in a feature link relations stored for a specific feature. The system can also determine all features that link to a specific feature, i.e. all feature that are source in a feature link relation to the specific feature.