Further to this discussion I'd like to add that we are using tags in a similar fashion, adding a requirement number and it's section to the list of tags. eg:

BRBPR,BRBPR01

This allows us to search for the requirement specifically and the section.  We have a wiki page which lists what stories were generated from a particular business requirement using this simple MQL query:

h2. Business Process Requirements

 {{ table query: SELECT number, name WHERE TAGGED WITH 'BRBPR' }}

Some bright spark asked if we could display the list of tags as values returned from the query, however I have been unable to find or discover a keyword that will expose the tags associated with a card.  The possible 'Tags' and 'Tagged' options result in an error inidcating the card doesn't have that property.

This post has two suggestions:

1. Expose tag values to MQL queries.  I can get them from an admin page, how about from an MQL query ?

2. Implement multi value lists.  Some of these issues could be sidestepped if a card property could contain more than one value.

Regards,

Jason.