Banjo Csus4 chord (Open D)C suspended 4th on the 5-string banjo: 3 1 3 3, and 4 more shapes

Frets, string 4 to string 1: 3 1 3 3 (first position)

1. String 4 (D): 3rd fret, middle finger, F
2. String 3 (F♯): 1st fret, index finger, G
3. String 2 (A): 3rd fret, ring finger, C
4. String 1 (D): 3rd fret, little finger, F
5. String 5, the short f♯: open, F♯, not in the chord

Sounds: F G C F  ·  Csus4 is C, F, G (1 · 4 · 5)

The 5th string: the short f♯ rubs against the F and G in this shape, a semitone away: some players let it ring, some skip it.

With a capo: on the 5th fret it’s 0 1 3 0 (frets counted from the capo), an open Gsus4 shape. Spike the 5th string at the 10th fret to keep it in tune with the capo.

Open D tuning: f♯DF♯AD, the short 5th string first, then strings 4 to 1.