When using the competency frameworks it's possible to hide/ unhide frameworks via the visible flag. However you are unable to do the same with the competencies within the framework.

The only way to not show a competency is to delete it or to remove it from the users learning plan.  If you delete it and then if you decide to reinstate it, then it will get a new id and thus not link to any existing reviews. If you remove if from the learners plans then this could take a very long time based on the number of users.

I can see many cases where show/ hiding would be very useful as people are perhaps changing the framework they deliver on a temporary basis. I think adding a visible option would be a very useful option.