How to replace poor or old gifs with MP4?
Hello,
I've seen that a lot of old gif posts got swapped with better quality mp4 or webm videos.
I wanted to help too and started uploading some precure and birdy decode mp4 videos.

How do I mark them as replaces for older or poor quality gifs?
I uploaded a mp4 video in dvd quality of a scene (http://sakuga.yshi.org/post/show/12608), but it got deleted, because it was a duplicate of this poor quality gif (http://sakuga.yshi.org/post/show/46). I don't really understand what I did wrong.
Should I mark the new one as a child post for the gif, that I want to replace? Or can I somewhere leave a note for the moderator?
Someone messed up, basically. Your upload's perfectly fine and has been undeleted. Sorry about that!

EDIT: As for getting old gifs deleted, just flag them for deletion and we'll get around to it.
Well yes, I messed up. My bad. I was the one who deleted your clip, but I should've specified the post that I was referring to.
http://sakuga.yshi.org/post/show/4620
It's supposed to refer to this webm, not the .gif.
Okay, I didn't saw that it was already webm'd. Thank's a lot for the fast answers ^^ I will pay more attention in the future.