A language only for Travellers

Shelta is a language spoken by Travellers, particularly in Ireland but also parts of Great Britain. It is widely known as the Cant, to its native speakers in Ireland as Gammon and to the linguistic community as Shelta. Although this aspect is frequently over-emphasized, it was often used as a cryptolect to exclude outsiders from comprehending conversations between travellers.The exact number of native speakers is hard to determine due to sociolinguistic issues but Ethnologue puts the number of speakers in Ireland at 6,000 and 86,000 worldwide.

Linguistically Shelta is today seen to be a creole language that stems from a community of travelling people in Ireland and Scotland that was originally predominantly Irish and Gaelic speaking which went through a period of widespread bilingualism that resulted in a language based heavily on Hiberno-English and/or Scots with heavy influences from Irish and Gaelic.

http://en.wikipedia.org/wiki/Shelta