Aha, here is the staring one that I saw (and I assume the OP) did as well:
(Poster says "Staring" in large font with the 'a' and 'g' altered to be two angry looking eyes. Underneath it says in smaller font but all capitals: "Intrusive staring of a sexual nature is sexual harassment and is not tolerated" and underneath that is the usual contact information for BTP)
Rail industry campaign will raise awareness about what constitutes sexual harassment, encouraging reporting and helping to make sure there is no unsafe space on the railway Research shows people don’t realise that behaviours like wolf whistling, leering/staring or deliberately invading personal...
media.raildeliverygroup.com
Personally I think that's very clear on what is an issue...