[DONE] - The feature was requested and it was implemented. You can already use it (http://www.magiclantern.fm/forum/index.php?topic=3068.0).
[ALREADY DONE] - The feature was already present in ML, so why requesting it again? In most cases, the user did not read the manual, or did not try the nightly builds, or did not even try to run ML (!).
[IMPOSSIBLE] - We can prove that it can't be done (e.g. lack of CPU power, or requiring extra hardware, or we would have to break the laws of physics). Or, we just have no idea where to start.
[WONTFIX] - We believe it might be technically possible, but we don't think it's worth spending development time on it. Feel free to investigate the problem yourself and submit a patch if you succeed.
[SCRIPTING] - It's a better idea to write a Lua script (http://www.magiclantern.fm/forum/index.php?board=53.0) that does what you need. Give it a try!