Requested feature overview description.
The option of removing an FFD you put on a post

Why would it be useful?
For if you make a mistake, like if your idiot browser autofills the ID of a superior post and you mistake it for the ID you were intending to input.

What part(s) of the site page(s) are affected?
The FFD part

All flags are still handled manually, so if there is situation where something was flagged wrongly, who is handling the flag should see this and remove the flag or correct it.

If you are flagging for inferior post and messed up ID, simply replace the parent post ID manually, things will then go correctly regardless of the ID mentioned in deletion reason.

I would say that situations for accidental flags that has happened when I have handled them, I can count with one hand fingers. Everything is always solved by regular flag handling, comments or dmail really well. So to implement this kind of system feels like waste of resources.

Mario69 said:
All flags are still handled manually, so if there is situation where something was flagged wrongly, who is handling the flag should see this and remove the flag or correct it.

If you are flagging for inferior post and messed up ID, simply replace the parent post ID manually, things will then go correctly regardless of the ID mentioned in deletion reason.

I would say that situations for accidental flags that has happened when I have handled them, I can count with one hand fingers. Everything is always solved by regular flag handling, comments or dmail really well. So to implement this kind of system feels like waste of resources.

Seems like something that may be a "waste" of resources now, yet would "pay" for itself down the road. Everyone has those times where there's a "duplicate" of a post and then someone brings up something like "Oh, no, wait, this one has X in the background there" or "There's this minor detail here but not here." Sure, it may not happen often, but I can definitely see how giving the person that flagged something the ability to remove the flag and fix a mistake themselves instead of waiting for staff to handle it would be a good thing.

As far as I can see it would just mean fewer bad flags for everyone to deal with in the long run and that doesn't seem like a bad thing to me. The time of the staff is valuable, spend some now to save a lot over time, seems like a good investment opportunity to me.