K-O in knitting means "Knit Over" or, in other words, pass one knit stitch over the next.
I Think It Means Kiss My A**
M means 'marker'. This is normally a small circle of plastic or metal or contrast yarn (I use paper clips or safety pins) hooked on the needle between specific stitches. For example, if you were...
There's a video game called Mortal Kombat, and that is it's abbreviation. I'm not sure about other possible MDKs.
millimeters or M M