Can I create my own chord symbols and scales?

Hi,
I am just wondering if I can create my own chord symbols and scales in Cubase.
Thanks!

Yes.

See:
Musical Scale Setup Dialog (steinberg.help)
and

Event Display - Chords & Pitches (steinberg.help)

Thanks for your reply!
Scales will be working as I expected but the custom chord symbols function seems to change the already existing chord symbol not adding.
For example, I wanna add Dyad chord symbol as 5 but when I created the chord, Cubase does not recognize my custom setup in Key editor…

Yup. 3rds are required for the algorithm Cubase uses.