It's not that complicated, and I don't recall any real issues over the matter.
stopped for questioning
witness to a crime or suspected crime
In addition, I would notify if I called THEM for an official purpose, such as to report a crime or suspected crime.
I don't recall ever seeing a SERIOUS issue over an "official purpose" stop. If there have been any, I'm sure they're outnumbered 20 to 1 by issues regarding "promptness" of notification, especially in instances where a sleazy cop tells somebody to remain silent, THEN charges them with failure to "promptly" notify. This happened in Beachwood. The guy managed to notify after 51 seconds. He was arrested, charged, tried and acquitted. I'd be VERY surprised if he didn't sue all involved.