What is "mattenenglisch"

Mattenenglisch, in Bernese German Dialect Mattenänglisch, is a name for the varieties traditionally spoken in the Matte, the old working class neighbourhood of the Swiss City of Bern. It is used in two different senses: Either for the traditional sociolect of that neighbourhood or for a special kind of Pig Latin that was used there. In the second half of the 20th century, both have fallen out of use because after the traditional social stratification has been completely changed, the Matte is no longer a working-class neighbourhood. However, there are voluntary associations that cultivate Mattenenglisch.