[GreenKeys] interesting article

[Jim Haynes]

Yes, and a number of interesting things about that telegram.  It was
sent on 20 December 1946, which was a Friday.  MZA219 is the circuit
identification and message serial number.  15 is the word count - the
address and signature are not counted.  The filing time was 6:14 PM
which would have been Central Standard Time.  The (25)  up in the top
of the form shows that the operator finished keyboarding the message
at 6:25.  The time stamp 1946 DEC 20 PM 8 26   was stamped on the message
when it had been gummed down on the form, and would have been Eastern
Standard Time.  So the message spent just about an hour in transit.
Maybe it was an operator or maybe the sender, but there is an extra
space between the end of MONDAY and the period.

It would take someone with a lot more knowledge than me to say how the
message was routed and how many times it might have been relayed by
reperforator or by re-keyboarding.  MZA219 was the number applied to
the message at the point it was sent to the destination office, previous
message numbers from earlier in the routing being stripped off.
MZ would be possibly mnemonic to the sending office, A is circuit number
A (perhaps the only circuit) and 219 is the actual serial number so it
was the 219th message of the day sent to the destination office.
The most likely suspect for MZ is Miami, since that's a big city
on the land route to the Keys.