Can't remove annotatation on item after removing protocol parameter of this annotation type.

[base]

How to reproduce: 1) create annotation type AT being protocol parameter and allow it for items of type IT 2) add protocol parameter PP of type AT to protocol P 3) create an ITEM of IT type, select protocol P and annotate with protocol parameter PP 4) remove PP from parameters of protocol PP

The ITEM will still have the annotation of type AT, but it will not be shown in list of ITEM's annotations, so it can't be deleted/altered. Is this desired behavior? Maybe one should not be able to remove protocol parameter if there are items using it?

I have not checked what will happen if instead of (4) one will change/unselect the protocol P for ITEM.