Tag No More
Security covered
This module prevents editors from adding specific taxonomy terms to content by hiding them from select list widgets. If a taxonomy term is marked to "Tag no more," it will no longer appear as an option in these fields.
Use case
You want to have some taxonomy terms on your site, but you don't want editors to be able to add them to new content. In other words, you would like to just delete the terms, but for whatever reason you can't - so you want to make sure they don't get used any more.
Limitations
This module currently only works on core Taxonomy Term Reference fields using the "Select list" widget type.
Usage
After enabling the module, edit any taxonomy term that you would like to hide from editors and check the box labeled "Tag no more", and then save.