All present and correct
Everything, or everyone, is accounted for.
Part of the British Army's King's Regulations - the Report of the Orderly Sergeant to the Officer of the Day, used to report that the roll-call was successfully completed. One of the numerous, and in this case probably spurious, candidates for the explanation of the word 'okay'; that is, OK = Orl Korrect.
The phrase was also in use in Canada/USA by the late 19th century. The Winnipeg Daily Free Press reported this item in January 1876:
"Inspection - Adjutant Rodman, U.S. Army, dropped in and inspected the FREE PRESS staff this morning, and found all present and correct."
It is now used outside the military on both sides of the Atlantic, although it isn't a frequently heard phrase.