HELP WITH "tuck" row please

Hi, Im trying to make a baby’s bonnet following a Sirdar pattern. You have to place a marker at the end of each row then continue with another 12 rows of pattern. The next instruction is:

Work tuck by picking up every stitch on the marked row onto a spare needle then work together 1st from tuck row and 1st from spare needle

Can someone explain how you pick up every stitch 12 rows down please.

Many thanks.

Insert your needle into the st 12 rows below and knit that st together with the one on the needle in the current row.