Greasy Fork

I don't understand "autoseen"

I'm seeing works show up in my history that I've never opened, but most seem to be from pages (e.g. a fest, an author's Works list) that I've looked at. Could this be a function of the autoseen function? What does "Mark as seen on open" mean -- what else would count as "Seen"?

"Mark as seen on open" means that every work you open (go to the work's page, not a listing) is marked as seen for the purposes of the userscript. Otherwise you need to use the "Seen ✓" button to mark it as seen. Seen works have a gray bar on the blurb. It doesn't affect your history.