ECO C34: King's Gambit Accepted
ECO C34 is part of volume C — Open Games.
The Lichess chess-openings dataset files 13 named lines under it.
The shortest is King's Gambit Accepted: King's Knight's Gambit:
1. e4 e5 2. f4 exf4 3. Nf3.
That position has come up in 19,286,909 Lichess games between players rated 1600 to 2500: White won 51.8%, 3.5% were drawn and Black won 44.7%.