I'm creating a custom taxonomy whose terms must remain fixed by all users. Once I've set up the starting set of terms, I want them to be immutable. I also don't want to clutter up the Admin UI with additional links and metaboxes where they're not needed.
public => 'false', or
show_ui => 'false' not only hides the manage tax link, but also prevents the user from assigning the term to a new post.
I need a way to hide the "manage" link within the post type pulldown, show the term selector metabox on the post page, but (hopefully) disable the "Add Term" option at the bottom of this metabox.
Does such a feature exist? Or are taxonomies always supposed to be user editable?
Custom taxonomy capabilities get me most of the way there, since you can independently set CRUD rights based on capability. But how to disable even admins from modification? (I know this sounds like a bad idea but it's viable.)