Dogwalkers

He knew of the dog owner rules when he bought his puppy.
When he saw another dogwalker in the park while he was walking his, he had to acknowledge them from afar like they were both owners of the same make of classic car meeting on a country lane and sharing a moment.
He knew that if he saw a fellow dogwalker walking their dog when he wasn't that he still had to greet them, but in a more casual way.
And he knew if he met a fellow dogwalker, but neither of them had their dogs with them that they were to ignore each other completely.
The politics were complicated.