Οἱ βασιλεῖς τῇ ἐγκυκλοπαιδείᾳ, αὐτὴ τοῖς βασιλεῦσι (Salamanca inscription) → The kings for the university, and the university for the kings
Of things: P. and V. ἑκούσιος, αὐθαίρετος, V. ἑκών.
Of persons: P. and V. ἐθελοντής.