My holding tank is polyethylene (please don't make me type that word again).
It's in good shape except it has a sort of dent in it, the surveyor said
it's from someone's big fat foot using it as a step. I believe he may be
correct.

I would like to put a sign on it that says "no step" but from remembering
other posts about getting things to stick to this stuff I'm not sure if this
will work. Any ideas out there?

Oh yeah, and where exactly do you go to get a sign that says "no step"?
Couldn't even begin to guess.