piano chord
Csus2
C1D2G5
The third replaced by the second. Nothing in it decides between major and minor.
What is true of it
Csus2 is C, D and G — 1, 2 and 5 counted from C.
These are also the notes of Gsus4/C. Which name is right depends on what is underneath and what came before — the notes alone do not decide.