The Glagolitic script is the first Slavs' script made by Konstantin Ćiril in 863 just before his trip to Moravian Slavs. The basic symbols of this script are: triangle which denotes Trinity, circle marking the totality of divinity and the cross as a symbol of Christ. Afterwards, Glagolitic settled among two lines and changed its shape from rounded to angular. This kind of angular Glagolitic is also called the Croatian Glagolitic. As a characteristic according to which we can differentiate rounded and angular Glagolitic, besides roundness and angularity there are: the existence or omission of nasal sounds, jery sounds, one or both semitone, the reduction of numbers which retained only numerical value, marking of palatalization, linear system and especially the morphology of certain letters. The most reliable materials for paleographic, lingual and historiographical study of the oldest Croatian Glagolitic stage are the oldest Glagolitic epigraphic fragments, dating from 11th century and found on Kvarner. Older than the Baška tablet are definitely the Plomin tablet, Valun tablet, Krk inscription, Glagolitic Konavle inscription and the incsription od Župa Dubrovačka, found on the southern part of Eastern Adriatic coast. In the 11th and 12th century there are Baška tablet and fragments from Plastovo, Supetar and Knin which are very clear indicators of lingual modification of formative Glagolitic period in Croatia