need help with a cable pattern, rep every foll 6th row

[darlenes22]

I am making a cable sweater, which has 20 rows to complete the cable pattern, I am confused, after completing the 20 rows I assumed that I just repeat it until the amount required for size, but it says "From 1st to 20th row sets C6B cable patt and twisted cable patt between asterisks, working C6B cable patt in next and every foll 6th patt row" Somebody please help I am at a stand still. Thanks