When you pay a small fortune per word, as people used to in sending telegrams, the desire to keep them short can become overwhelming. Here's a few examples, the first from Leo Rosten's The Joy of Yiddish and its successors, and some of the others from an essay by Stephen Jay Gould.
Mrs. Gershenbaum, in Moscow, sent a telegram to her husband in Kiev: SAYS TO OPERATE OPERATE. Mr. Gershenbaum replied: SAYS TO OPERATE OPERATE.
The police promptly arrested Gershenbaum: "What secret code are you using?"
"No code," said Gershenbaum.
"Do you take us for fools? Just read these telegrams!"
Well, my wife is sick in the kishkas. So she went to Moscow to see a famous surgeon, and she wired me: 'Says to operate. Operate?' So I replied, 'Says to operate? Operate!'"
Victor Hugo wanted to know how Les Miz was selling, so he cabled his publisher "?", who replied "!"
This tale of two telegrams is told of Shaw and Churchill, but also of other pairs:
SENDING TWO TICKETS TO FIRST NIGHT BRING FRIEND IF YOU HAVE ONE.
CANT MAKE FIRST NIGHT WILL ATTEND SECOND IF YOU HAVE ONE.
London wanted to know if a certain general had pacified the Indian (now Pakistani) province of Sindh. He replied: PECCAVI ("I have sinned").
And then there's following terse summary of a one-man research expedition sent from Britain to ransack the streams of Australia to discover the truth about the duck-billed platypus: MONOTREMES OVIPAROUS OVUM MEROBLASTIC.
An American tale: The newspaper owner William Randolph Hearst sent the astronomer Percival Lowell the telegram IS THERE LIFE ON MARS CABLE THOUSAND WORDS PREPAID. Lowell was a bit discouraged until his eye lit on the last word. He replied NOBODY KNOWS NOBODY KNOWS NOBODY KNOWS NOBODY KNOWS NOBODY KNOWS NOBODY KNOWS NOBODY KNOWS NOBODY KNOWS NOBODY KNOWS ....
Another story about India: A general sent a carefully worded telegram in favor of his nephew to another general nearer the front. The original text was "I commend Dowbiggin [the first general's nephew] to your attention, if he is fit for it." In those days, it was customary for telegraphists to compress telegrams themselves, and so it arrived as LOOK AFTER DOWB.