Sorry for the delay in response. Tags are used to "tag" an artifact in the repository with a certain name/value pair (such as tagging a rule with county=USA). In addition, this can be done ad-hoc without changing the repository structure or model as with adding new properties to the rule model permanently. Later, tags can be used in queries to find rules as well as other areas of the product such as reports, extractors, etc. If the same tag is used consistently for all rule artifacts, it would be preferrable to add a permanent custom property to the rule model extensions.