>Stitches should be a multiple of 7, plus 4 (2 stitches at each end).
Place 3rd and every following 7th stitch into NWP, knit required number of rows and rib up ladders as usual.
This is a good all over pattern (with purl side as right side) so do the first 10 or 20 rows with a smaller size keyplate to define the rib edge.
The sample was knitted on the Bond using DK yarn and the old keyplate 2.
Talk to you later,