of in Bulgarian

(following an adjective) Introduces its subject matter. [from 15th c.]

Links to a genitive noun or possessive pronoun, with partitive effect (though now often merged with possessive senses, below; see also double possessive). [from 13th c.]

Belonging to, existing in, or taking place in a given location, place or time. Compare "origin" senses, above. [from 9th c.]