The team were the first to perfect “long goal” (scoring from further down the Quidditch pitch and outside the usual area). They also have a reputation for giving chances to young unknown players (QA8).
Vratsa, a city in northwestern Bulgarian, does not have a Quidditch team (or any other sports team) listed its Wikipedia entry (Wikipedia).
The Bulgarian for Vratsa Vultures is Врачански Лешояди (with thanks to Lexicon reader Zahn).
Lexicon list of World Quidditch teams