Requested feature overview description.
A confirmation prompt on the "Mark all as read" option on the forum subnavigation

Why would it be useful?
I accidentally click it pretty often and lose track of which topics I've read or not, I can't be the only one that dumb. Having a confirmation prompt would make it harder to accidentally mark everything as read since it would require two clicks.

I don't think it should be too annoying for people who regularly click the button?

What part(s) of the site page(s) are affected?
The subnavigation bar for the forum.

I've never misclicked on it, though I can certainly understand others doing it. I don't like the idea of a confirmation on it. Maybe the button could be moved to avoid misclicks? Or you could use a personal userscript to require confirmation?

IDK if it works on PC, but on a mobile you can go back one page to see what pages were unread, if you accidentally clicked mark all as read. IDK if this works on e6's mobile mode this works on mobile mode too, but and i can confirm that it works on desktop mode since i just tried it.

otherwise, i wouldn't be opposed to the idea.