[OffJumpsJack]

Most patterns use 'sm' for slip marker, not move marker. I don't think I've seen a pattern write 'mm'.

Perhaps it is because I frequent the crochet section more than the (knitting) Pattern section. I am sure I saw more than one pattern using the mm notation. They were aniguri or some funky work for little stuffed animal patterns. Yes, I am sure it was in crochet patterns for in-the-round work. You have to move the marker in crochet as it is through a stitch (or around a post) and not on a needle as it would be in knitted patterns.