Latrinalia

In an uncredited Guardian article on privately-public graffiti
a woman writes:

'scribbles in women’s toilets express more vulnerability,
talk about relationships, and show more solidarity,
– while men are more likely to draw pictures and write insults.'

But a man wrote this in Solignac in 1981:

Then there were the glory-holes...

see also: 
https://www.theguardian.com/artanddesign/2019/dec/02/les-tasses-war-and-pissoirs-how-the-debauched-urinals-of-paris-helped-to-beat-the-nazis