One issue that hasn't been discussed much is what happens when a
glider flies cross-country between different TRACON jurisdictions. We
have three possibilities in Arizona - 0400 (Tucson) 1200 (Phoenix) and
1201 (New Mexico and some other surrounding locations). I have flown
in all three with my home 0400 code and no-one appears to have
noticed.

I suspect if you chose any random 4-digit number, no-one would notice
either.

It's definitely time for some uniformity, at least if anyone is
watching!

Mike