Another really common one which always gives headache, flagging posts as being "too big/large".

We have 15000×15000 pixel and 100 MB limit for extremely good reason, because we want them big (artists, remember to optimize your PNGs so they are nice and lubed). In most cases I will most likely ignore this flag and delete any lower versions as inferior. If users are having issues with larger files, they can enable samples in their own user settings and samples are now also default for guests. They are also free to blacklist or exclude huge_filesize and/or superabsurd_res from their results.

If you are artist or first party (character owner, commissioner), then simply say that the upload was accidental instead (e.g. artist meant higher quality variation for personal usage only, etc.). Artists can ask us to connect their account with artist wiki, so that we can directly see they are verified who they are and act accordingly or simply state "I'm commissioner" in reason and it's usually no brainer for us especially if you normally post commissioned artwork.