I have an "official" vocabulary and a "user-submitted" vocabulary. Content can be tagged from either list, and new user-created terms go into the user-submitted vocabulary.
Periodically, I will merge / rename the user-submitted tags to conform to a standard style, and then move them to the "official" vocabulary. This works well, except when users add a term that I later merge or remove - someone else is then free to add it again later.
So, how can I create a "blacklist" of terms that are disallowed for one or more vocabularies? Ideally, if a user tried to add the term as a free-tag, they would get an error when the form is submitted.
I'm using the following modules, if it makes a difference:
- Content Taxonomy
- Taxonomy Formatter
- Taxonomy Manager