What does the cryptic crossword clue "Some school’s outing returning to capital (4)" mean?

The definition is "capital". The wordplay uses a hidden word. Hidden reversed in "some schoOL’S Outing returning to capital" The answer is OSLO.

Some school’s outing returning to capital (4)

Guardian Cryptic #29670 | 22 Across | 2025-04-16 flower