Church Slavonic language
Since the 9th century there is in Croatia a unique phenomenon in the entire world of Catholicism, liturgy that was held in Church Slavonic language with special Glagolitic script (Pope was allowing serving liturgy only in Latin). Despite the various disputes, Pope Innocent IV approved use of Church Slavonic language and the Glagolitic script to Filip, bishop of Senj, thus making Croats the only Latin Catholics in the world allowed to use a language other than Latin in their liturgy prior to the Second Vatican Council in 1962.