Apparently its been around for a while, but just got made public: http://www.thestar.com/news/gta/torontocouncil/article/820835--ticket-cancelling-manual-released Its a downloadable PDF on the LH side of the article. I bet other cities have similar instructions for their people.
Who didn't know that stuff?, just ask any cop you know. Basic common sense, the cops have all kinds of leeway with a lot of things. My daughter's boyfriend is a rookie, mini-cop with a big attitude, like a little lap dog that thinks it's a Doberman. He's on parking ticket writing detail right now. My mini-daughter told me he gave a bike a parking ticket and the perpetrator came out of the store it was parked in front of and told him he was a pig with a Napoleon complex. I respect the law, they're judge and jury on the streets, the thin blue line that separates us from anarchy and the lawlessness of the forest beasts, even the wee ones.
Most cities in Canada have farmed out parking fines to private companies, leaving the police to police. But the cities write the guidelines under police and judicial consultation (can they win or lose tests). It seems that they figure the bad press would hurt the politicians more.