Hidden categories behavior in post editing form
|Priority:||Should have||Due date:|
Hidden categories are still displayed in the category selector when editing posts and clicking actually selects them. However, they are silently removed from the category field upon saving the post.
Correct behavior would be:
1. Do not display them in the selector tree at all
2. Display them in the selector tree but disable selection and indicate the status visually (greyed-out)
3. Make them selectable and save them, just don't show them in the FE
Each possibility has its merits. The third one would allow editors to prepare new articles for a new -- hidden -- category, also assign it to old articles, and publish the changes simply by making the category visible.