Help understanding a pattern by alice Starmore

It says keeping with the continuity of the rib, rib7(4,1) rib 7 being the smallest size, I want to make the largest size, but I don’t understand what rib 7(4,1), then it says make 1, rib six, when it says rib six does this mean knit one , purl one for the ribbing? and back to rib 7, does that mean rib seven knit one, purl one and then add four more ribs to make the pattern work out? I have knitted scarved and cabled hats, but it just usually says knit 4 purl one, easy to understand directions, these direction are hard. I would appreciate anyones help. please email me and thanks Vickie

The numbers in parentheses are for each size. For the smallest size, you rib 7, for the medium, rib 4, and for the largest, rib 1.

It’s telling you to ‘rib’ rather than to knit or purl because at each direction you could be at a different point in the ribbing. Look at the knitting. If the next stitch is a knit as it faces you, knit it. If it’s a purl, purl it. This will keep the ribbing lined up as you make any changes.

It means to do 7, 4 or 1 st/s in the rib pattern, depending on your size. Then after an inc, do 6 sts in ribbing.