Don't have a plumbing problem, only a question that is driving me crazy. On a recent plumber lead II position test, there was a question... define the following s-s-s-s
I did not have a clue and no one I ask seems to know the answer. I can not find anything on the internet or in any of my books.
Does it mean anything relating to plumbing, or was it a typo?
Thanks for your help