[EAS] Draft response to FEMA's recommended changes to EAS (FCC 21-77)

[Sean Donelan]

For folks which want to blow their mind, the allowed character set is 
much broader than most people assume.  The PSSCCC location could contain 
alphanumeric and special characters. Although, I don't think any current 
equipment would handle it well :-)

NOAA/NWS specification:

"The authorized set is ASCII characters decimal 10, and 13 and decimal 33 
through decimal 127. ASCII characters decimal 43 and 45 may not be part of 
the six character location code, but used only at the end of the block as 
shown previously in the symbolic form. The ASCII character decimal 42, 
(e.g., '*' ), is reserved for use as a wild card only."

While not explicitly stated in the specification, because it was standard 
practice in the 1980s, the Carriage return/Line feed are probably 
intended as message separators, not used within a message. And the Delete 
character (DEL) was ignored or skipped within a message (teletype paper 
tapes).

Spaces (ASCII 32) were allowed in the LLLLLLLL code as the padding 
character. Spaces were not allowed anywhere else.

In addition, the NOAA/NWS specification stated

"Numbers from 900 to 999 are reserved for assignment to unique non-FIPS 
defined alerting areas adjacent to facilities that store or produce 
nuclear, chemical, and biological material."

NOAA/NWS was already thinking about using all-nines "999999".

"Note: The geographic code 999000 will likely be replaced by the 
geographic code 999999 shortly after the FCC updates its EAS rules in 
late 1999. This will be done to create an entirely unique practice or 
demonstration county geographic area and to avoid any potential conflict 
with future wild card applications for the use of the 000 'county' 
geographic codes."

The FCC didn't update its rules. While introducing new mistakes, the FCC 
omitted parts of the protocol specification.