I don't mark either. I will try to describe the location but also include verbiage about such as.... and there may be others not seen. The language always says the specialist should inspect the whole area or system since what I'm doing as a "generalist" will not catch everything.
I've had owners have the contractor in for repairs and insist on only doing what I actually called out and ignoring everything else.
The other side is the contractors get greedy and try to "sell" more than is needed.
Dana