Rroma, besides the various names that are given to them by Gadže, are using other names to describe themselves - their group appurtenance. Groups should not be mistaken for clans or lineages, for these are subdivisions of groups, and can vary in size from a few thousands (like the Lotfitka Roma, the Latvian Rroma) to above a million, like the Balkan Arlii. These Rroma groups stem most probably from a common history and unity in trade and traditions that is reflected one to one in the variant of Rromanes they are speaking.
To take but one example, the Xaladitka Rroma, found from Eastern Poland to Russia and other countries were all horse-dealers and musicians, spent a long time in Germany, most probably between the XVth and the XVIIth century, reflected in their large German vocabulary, passed to Poland, and finally arrived in Russia proper in the XVIIIth century.
Broadly speaking, there are four main streams of Rroma groups: The Balkan Rroma, with a rather large Turkish vocabulary; the Vlax Rroma who migrated to present day Romania and have a large Romanian influence in their dialects; the Carpathian Rroma, found in the Czech and Slovak Republics, in Hungary and in Austria with a stronger layer of Slavic lexemes in their language; the Nordic Rroma, with a strong German influence.
The most common and best known groups are:
Balkan: Kirimlides, Arlii, Erlii, Jerlides, Sepetčides, Bugurdži, Kalajdži, Drindari.
Carpathian: Czech, Moravian, Hungarian, West and East Slovakian and Burgenland Rroma
Vlax: Servi, Vlaxurja, Rišarja, Kalajdži, Vlax, Džambaši, Laxora, Gurbeti, Cerhara, âurar, Mačvaja, Patrinara, Lovara, Dirzara, Mašara, Kalderaša, Rudari, Bejaša, Ursari, Lingurari and Gurvara
Nordic: Abruzezzi, Calabrezi, Cale, Kaale, Lotfitka, Manouches, Volšenenge, Polska, Sinti, and Xaladitka