Editing Topic map (section)

==Ontology and merging==
Topics, associations, and occurrences can all be typed, where the types must be defined by the one or more creators of the topic map(s). The definitions of allowed types is known as the [[Ontology (computer science)|ontology]] of the topic map.

Topic maps explicitly support the concept of merging of identity between multiple topics or topic maps. Furthermore, because ontologies are topic maps themselves, they can also be merged thus allowing for the automated integration of information from diverse sources into a coherent new topic map. Features such as subject identifiers ([[Uniform Resource Identifier|URI]]s given to topics) and PSIs (''published subject indicators'') are used to control merging between differing taxonomies. Scoping on names provides a way to organise the various names given to a particular topic by different sources.