Will someone please translate for me?

I do not understand these instructions (for shaping armholes):

“These 2 rows set the sts–armhole edge slip st selvedge and rem sts in st st.
Cont as set until armhole measures 20 cm”

I’ve already cast off a few sts on each side and made the inward curve of each armhole. The above quote is about the straight vertical part.

Also, when measuring the armhole, do you use a flexible measuring tape and curve it along with the holes or just hold it straight up and down and measure 20 cm from the bottom of the armpit up to the shoulder?
Thanks very much!

It appears to say that you should work the two rows in Stockinette Stitch, slipping the first stitch of each row.
I measure straight up and down, not along the curve.

Someone else might have some insight into those directions, though since it is a bit cryptic.

Thanks so much! I suspected it was what you said, but the wording is so weird…