The value singular applies to common and proper nouns. The criterion is a morphosyntactic one and not a semantic one.
numb=sg | |||
D e s c r i p t i o n | E x a m p l e s | ||
Common nouns | la moneta/sg | ||
lo studente/sg | |||
il dollaro/sg | |||
Proper nouns | Maria/sg | ||
Mario/sg |