In article , Mike Coslo
writes:

If a ham punches in 911 on his or her HT on our local repeater system,
the call will indeed be patched into the local 911 center.

That's an excellent thing for your local repeater. It isn't a national
standard among U.S. amateur radio repeaters, de facto or de jure.

The 911 combination IS a national standard for all telephone ESSs
in the United States and is accounted for in all number
combinations used in signalling and dialing in the telephone
infrastructure.

Your repeater's "patch" connects to the telephone infrastructure.
As such, amateur radio enables connection to an emergency
center...through the telephone system. The "patch" is entirely
voluntary and not universal.

LHA / WMD