***In slip stitch knitting, it's not an increase if you slip the next stitch. It's an increase if you knit the next one. ***
***Yes, where it says to slip with yarn in front, bring it to the front, slip the stitch, then bring it to back again. The yarn in front over the stitch creates a particular look for the pattern. ***
FWIW, I have done stitch patterns where there's a slip with YIF and then a K is done w/o moving the YTB (resulting in an increase). May not be applicable in this case.