[aprssig] APRS Priority bit

[Tapio Sokura]

Robert Bruninga wrote:
> Using the overlay-case-bit does not require any modifiction al
> all existing software.   But using a SUBNET would, else no one
> would see the priority traffic...

I don't agree here. The spec as it is -- or at least as it was before 
you got this idea -- for overlay characters is 0-9 and A-Z. So software 
has been written that will only accept overlay characters that are 0-9 
or A-Z, in upper case. Anything else causes packets to be dropped to the 
floor, in some software implementations.

This is the same thing as the operator-present-bit. The original spec 
had the hemisphere indicators in upper case only, so some programs are 
written to only accept upper case indicators.

I'm not saying things can't change in the APRS spec. But changing 
something and then claiming that the change doesn't require 
modifications to any existing pieces of software just isn't true.

   Tapio