It seems that the square bracket in this filename was possibly treated as an array in one of the processes by which swfchan grabs threads. Anyway just thought that swfants should know so that this could be checked for security reasons.

Here's the flash in question http://swfchan.net/42/POGZ4VT.shtml you can see the original name has it as megacum[0].swf while the archive has it down as just megacum.swf

So this thing is a bit of laziness from my part but also (second reason) were a thing because I remember other people sometimes used to post these filenames with "[2]" or "(2)" appended to them, because they had gotten them from Temporary Internet Files or from copying them into their own massive flash folder, and didn't bother to rename them when uploading to /f/. So swfchan trimming that part from the filename prevented flashes to have a bunch of different seen filenames that were really just supposed to be the same. Filenames starting with "Copy of " or ending with " - copy" also gets modified to trim those appended strings.

Rarely has this been much of a problem, only the "anon partyhard 2.O" flashes comes to mind. Originally that series was intended to end with brackets, I remember him mentioning it in a thread on /f/ where he were surprised the filename changed on swfchan, so he tweaked the filename format of the series. If I had made swfchan today I might not have implemented this "renaming of copied files"-thing, but on the other hand it would be pretty annoying if we were to start seeing a bunch of duplicate filenames separated only by strings clearly appended automatically by programs. Regardless I'm not going to change it now because although I think it would be safe I can't be sure I never wrote some function somewhere that assume the filenames always have those modifications.