PM (place marker) Place marker in│around│through stitch just made or as instructed.
Stretchy Bind off
Bind off is worked in pattern; knit the knits sts, purl the purl sts, adding a YO before working every other stitch, binding off both YO and st as one.
K1, bo (slipping 1 loop over), yo, k1, bo (slipping 2 loops over), k1, bo (slipping 1 loop over), p1, bo (slipping 2 loops over), p1, bo (1),