The "manage categories" screen has two interfaces, one when you first click on "Categories" which is used to add a new category and another once you click on an existing category to edit it.
I've added some custom fields to the Category editor, but I only want them to be present on the edit screen, not the "add" screen.
However $pagenow in both cases, is the same (edit-tags.php). The only difference I can see is that when editing, the action=edit token appears on the querystring.
Should I simply wrap my "edit_category_form" filter in a test for the existence of that token or is there a better way?
PS: I'd be fine with leaving the fields on the add screen, however, it appears that the save is ajaxed, and none of my custom fields are being saved in that routine.