The taxonomy service should allow to add a hierarchical classification of any kind of items in ILIAS. Currently the use of this service is envisaged in two components, glossaries and wikis, but it would not be limited to be used in content-related components. It should also be possible to implement "system-wide" use of taxonomies (similar to content styles).
 
Example use in glossaries and wikis
 
Since both glossaries and wikis have a initially a flat structure of items (glossary terms and wiki pages) it is sometimes of value to put these items into a structured classification, into a taxomony. Two concrete use cases are currently the driving forces:

• The Unirep project stores juristic judgements in glossaries and needs to be able to classify these judgements. Even if this may not look like the initially intended use of glossaries the need to classify glossary terms could be a common one.
• The ILIAS online help project would like to manage help articles in a wiki. However these articles should be classified, e.g. by ILIAS components and subcomponents, to give the content a clear structure that goes beyond simple linking between the articles.

Taxonomies should be a optional feature within glossaries and wikis.
 
Taxonomy editing and general use

Taxonomies are a hierarchy of classification and stored in a tree-like structure. They can be edited similar to chapters in learning modules or competences in the administration. The component that uses the taxonomy can assign items to the nodes of the tree, e.g. the glossary can assign glossary terms to the classification nodes of the taxonomy. The taxonomy service should provide ways to visualize and manipulate the classification. E.g. in glossaries it should be possible to activate a tree-like left-hand navigation of the taxonomy that lists all assigned term on the right.
 
Use Case Scenarios (example: glossary)

• Activate taxonomy option in glossary
• Add a node to the taxonomy
• Rename a node in the taxonomy
• Move a node in the taxonomy
• Remove a node in the taxonomy
• Add item to taxonomy node
• Remove item from taxonomy node
• Set ordering of items or subnodes within a taxonomy node (manual and alphabetic ordering should be supported)
• Export/Import a taxonomy