I’ve heard of some, but cannot point you to a specific one.
Keep in mind dept of Ag requirements, such as # of chickens sold at one time. In Ohio that was/is (?) 6 chicks, so an ordinance of 4 would be odd.
Don’t count chicks. So, only applies to young chickens 3 or 4 months old and older. Then, if someone purchases 10, but are only allowed 6, they can ID any boys by 3 months old and be able to remove them. Or, if someone does a 4-H project on meat chickens, they are hatched and out the door by 8-12 weeks. Most males aren’t noisy until closer to 10-12 weeks and their crows don’t carry very far until they are older than that.
Spacing of coop -usually it’s noted that the coop has a setback of x feet from property line or neighbor home. Make sure that a coop could be placed in most yards then. Some limit size of the coop, but I’d recommend that a shed size could be fine (whatever local shed policies are) so that the coop could be repurposed if chickens are no longer kept there, or the reverse: a shed currently there could be turned into a coop.
Don’t let a neighbor be easily able to “complain” and the chickens are removed without any proper recourse. Does the city/town remove dogs based on one noise complaint? Probably not.
Is the ordinance for “chickens” or “poultry”. Maybe it can say 12 chickens, or 4 ducks, or 12 cotournix quail (this is the usual quail for eggs, not usually considered wild birds), or 2 turkeys -or a combination not exceeding individual limits and maximum of 12 total, so a family with 2 turkey, 4 ducks and 6 chickens does not exceed that ordinance, as an example.
Fencing requirements: must be fenced in, the back yard at least. Cannot free range past boundaries of yard.
Extra chickens: Ordinance works for up to 0.5 acre (add minimum if needed). Every 0.25 acre allows 3 or 6 more, with a max cap at X poultry. Keep in mind, a 500sqft run can hold 50 chickens: 50x10 ft or 20x25. That’s really not huge.
You might even require the feed and treats to be kept in rodent proof containers.