… and other sex-related accoutrements
To be fair, the rule is not British at all, and applies to other nationalities as well. (It’s actually a new ordinance from a city in Spain that gets inundated by British tourism.)
It is “forbidden to walk or remain in the streets only in underwear, or with clothes or accessories that represent genitals or with dolls or elements of a sexual nature”.
The fine could rise to as high as £1,300 if the offender is with a disabled person. (??? I did not make that up.) I guess that will tend to negate the value of traveling with a disabled person to get a better parking place.