The "kuippo" rings you might be thinking of are actually the signature rings worn by the characters Troy Bolton (Zac Efron) and Gabriella Montez (Vanessa Hudgens). However, these rings were not meant to have any writing on them, symbolizing their commitment to their friendship and their dreams.
There's a lot of speculation and fan theories about the meaning of the rings and whether they hold a special significance. However, the actual meaning was left intentionally ambiguous in the films, adding to their charm.