These six nations alone are considered Celtic by the Celtic League and the Celtic Congress, amongst others. These organisations ascribe to a definition of Celticity-based mainly upon language. Celtic languages have survived (or in some cases been revived) and continue to be used to varying degrees in these six geographical areas. There are also Celtic nomads: Irish Travellers called "Pavee" that speak a language called Shelta that is a creole of Irish Gaelic and other languages, and Indigenous Highland Scottish Travellers called "Tinkers" who speak a language called Beurla Reagaird that is an acrolect of Scottish Gaelic.