The flag label UI description says:

A short, descriptive title for this flag. It will be used in administrative interfaces to refer to this flag, and in page titles and menu items of some views this module provides (these are customizable, though). Some examples could be Bookmarks, Favorites, or Offensive.

But we're using this in the edit form, which is user-facing.

We either need to make this clear in the UI description, or use something else in the edit form.

We also need to make it clear what you'll get in the edit form, without having to either try it out or crack open the code.