What is "utraquism"

n. The doctrine of the obligation of the faithful to receive communion in both kinds (''sub utraque specie'').

Utraquism (from the Latin sub utraque specie, meaning "in both kinds") was the principal dogma, and one of the four articles, of the Calixtines or Hussites, who maintained that both the bread and the wine should be administered to the people during the Eucharist.