Chords can alo be notated by their symbol; this is especially useful for guitar players or any othe rmusician playing acoompaniment.
Chord symbols are notated between ", and inserted right before the first note they’re played with.
X: 1
| "Cmaj"CE FE |
The usual notating conventions can be used with ABC chord symbols: you can have maj, min chords, and you can specify the bass note; more details on The ABC standard page.