Before wireless, there were Morse telegraph abbreviations used by the
different wire telegraph companies.
The operator responded to his own station call or "CQ" and ignored
everything else.
"CQ" and "3Ø" are two abbreviations which have survived. CQ alerts all
operators on the line for a company message or "news" for delivery to
subscribing local newspapers, and "3Ø" was the "end of traffic" sign.
The difference between landline Morse and what we use on the air has changed
some of the prosigns we use to different characters that sound the same as
the original long Morse character.

The operators learned to automatically "copy" Morse without "reading" it.

An example of "landline news" was the story that President Lincoln had been
shot. The legend goes that in many Midwest and western towns, the telegraph
operator copied the news and sent it to the newspaper with the regular batch
without consciously reading what it meant.
So the operators were astounded to hear the paperboy selling the "EXTRA"
newspaper edition with the bulletin - until they checked their carbon copies
of what they had sent to the newspaper office.
-3Ø-

73,
Pat W5THT