All the content in this RNA-site has keywords added (content metadata). These keywords are derived form a reference structure. The concepts of this reference structures have a description about the meaning of the concept. This description is called a "lemma".
It is possible that a lemma of a certain concept contains keywords of other concepts. What we have done in this site is to establish links between those keywords in lemma's and the lemma's which describe them. The result is a network of keywords, a lemma network, that exists independent from the hierarchy of the reference structure itself.
To demonstrate this:
Another demonstrator of a lemma network is the RDF-version of the Verschueren dictionary of RNA-partner Dutch Libraries.