Obligatory Field

I've been working on another team's project and stumbled upon the following version history of a class that I was editing.

Version history comments, by four different authors.

I'm a bit of a Nazi code commentator, I'll admit to that, but 'm'?  I sent an email (containing the letter 'm') to a few of the team members but got no feedback as to what the meaning of 'm' signifies nor if it was part of internal standards or practices.

Happy April Fools Day, says I.