In the Sherlock Holmes book A Study in Scarlet, Mr. Watson asks about a man in the street and Sherlock Holmes deduces that man is a retired marine sergeant:
"You mean the retired sergeant of Marines," said Sherlock Holmes.
Then the man comes to the house which Sherlock Holmes and Watson lives and here is the dialogue between Watson and the man:
"May I ask, my lad," I said, in the blandest voice, "what your trade may be?"
"Commissionaire, sir," he said, gruffly. "Uniform away for repairs."
"And you were?" I asked, with a slightly malicious glance at my companion.
"A sergeant, sir, Royal Marine Light Infantry, sir. No answer? Right, sir."
I thought here the man was indeed a marine sergeant but he was not retired, Holmes thought so as he was without uniform because the uniform was "away for repairs."
But in the next chapter Watson and Holmes had this dialogue:
"How in the world did you deduce that?" I asked.
"Deduce what?" said he, petulantly.
"Why, that he was a retired sergeant of Marines."
Watson accepts not only he knew he was a sergeant of Marines but also he was retired. After that Holmes explains how he figured out he was a sergeant of Marines but did not mention neither how he figured out he was retired nor he was wrong about that one.
In the dialogue between the sergeant and Watson is there anything implies the sergeant was retired? I thought 'Uniform away for repairs' as 'My uniform is away for repairs'. Is it an idiom about being retired?