Max length for reason of editing or deleting posts

[Gwendolin]

Hello, is there a hack or a howto, how I can change the max length for input reasons for edit or delete posts?

Often for me is a count of 125 maximal input is not much enough to tell a user, why I'm deleting his post/thread.

I'm using the modification that the user get a pm, if I delete one of his posts and I would like to tell him a understandable reason in one message.