There isn't really "a" maximum count. There's a variety of enforced limits. If the standard(s) even set an official one, it's not something a lot of things pay

There isn't really "a" maximum count. There's a variety of enforced limits. If the standard(s) even set an official one, it's not something a lot of things pay attention to. You also can encounter problems with things like command lines enforcing their own limits, making a URL that your browser may or may not be happy with not be something you can directly curl or wget.