I've seen a lot of fics disappear from my bookmarks, some 10+ years old, because they were added to an unrevealed collection. It makes me wonder if people realize what your fic being added to a collection actually means and if the authors approved it automatically without realizing what would happen.
If someone adds your fic to their collection, they can hide it! They can mark the collection as unrevealed and your fic will be unreadable to anyone other than them! If you're writing works for a surprise event, like a Secret Santa, this is really nice.
But if you're just writing and someone adds your fic to a collection for their own personal use and marks it as unrevealed, that. . . really sucks.
I bookmarked this fic in 2017, almost 5 years ago. Knowing me, the fic itself was probably at least a couple years old at the time I bookmarked it.
This is a 5+ year old fic that is completely inaccessible now because it was added to a collection that, as far as I can tell, is literally just for the collection owner's own reference. There's almost 30 fics in the collection, all of them unrevealed.
Please don't blindly accept collection requests and if your works ARE in a collection, make sure that they aren't being hidden without your knowledge or consent.
Are you able to remove a work from collection after you allow it or is it just a story that's just fucked?
Yes, you can remove your works! From the faq:
If you're the creator of the work:
1) Select the "Edit" button from the work's page and scroll down to the "Associations" section.
2) Select the red (×) beside the collection name you want to remove next to "Post to Collections / Challenges".
3) Select "Post" to apply the change. The work will be immediately removed from the collection.
I'm not sure if you get an alert if your fic is marked as unrevealed though, so keep an eye on the collections that your works are part of.
There's also an option in your preferences to accept collection invitations automatically. I would highly recommend making sure that that option is not selected.
I realize this might be a dirty trick pro-censorship fandom harassers might try to pull on some people, so yeah.
Boosting for visibility.
Boosting because this is really, really important!
Please stop circulating this version with FALSE/OUTDATED information. AO3 has changed this feature. Now, works can only be Unrevealed if the collection is Unrevealed at the time works were approved by the author for addition to the collection. Changing a collection to Unrevealed only affects works added after that change. Authors can remove their works from collections at any time unless they have orphaned them. This is why adding to an Anonymous Collection is so much better than orphaning them.
This was an issue in the past, as Unrevealed collections were designed for events where fics get "revealed" at certain times and were not designed to prevent bad actors or just ignorant actors from using them to "hide" existing fics, just like the tagging system was not designed to prevent bad actors from tagging every possible unrelated thing to try to increase their readership or just be a jerk. It's a testament to our wonderful fandom community that sometimes it takes years for features to be abused in a way that reveals these weaknesses.
That said, most people would benefit from making collections of bookmarks rather than fics. AO3 has a lot of information about this, and has in fact debunked this concern about hiding fics specifically in recent years but unfortunately the debunking info is harder to find than FAQs which described mostly how to use the site features properly. https://archiveofourown.org/faq/collections?language_id=en#whatiscollection