How might I disable the slug edit button for any post that has ever been published?
I want to disable the slug-edit (my permalinks) button on post.php for any post that has ever been published, which includes posts that were once published and then unpublished. However, after having looked at the SQL database after I made a dummy post that I first saved as a draft, and then scheduled, and then published, and then unpublished (put back into draft), I couldn’t identify anything that could be used as a way to determine if it ever was previously published.
How might I do this without editing core WP files? I thought about adding a post_meta value for any post that ever gets published; and the value would never change. It would be boolean, and set to true on publish. Then that value would be checked. However, I will not go into the core WP files.