Maximum length of identifier in -initWithCenter:radius:identifier: of CLCircularRegion

Question

What is the maximum length allowed for identifier property in - initWithCenter:radius:identifier: method of CLCircularRegion class used for region monitoring?

- initWithCenter:radius:identifier: is returning nil when the identifier length exceeds a certain limit. So what is that limit?

Answer 1

The max length is 512.
If it is exceeded, I get in iOS 14 the log

[Client] {"msg":"identifier is too long"}  

A longer ID fires also a runtime breakpoint.