It's pretty simple. Users submit an edit to add the tag arranged marriage, and they have to add an explanation of how this tag applies to the show/who in the show is the arranged marriage between. Then the approval staff decide if it applies or not and approve it.
I obviously have not seen all the titles tagged with it, so I'm not sure which titles you don't think belong tagged with it, but any user ca submit an edit to remove tags that don't fit the drama. But you must also provide an explanation of how there is no arranged marriage in the title.
