Rövarspråket (English: The Robber Language) is a Swedish language game. It became popular after the books about Kalle Blomkvist by Astrid Lindgren, where the children use it as a code, both at play and in solving actual crimes.[1]
It was used by robbers on the Swedish island Gotland as they didn't want the Visby Garrison to understand what their plans were.
The principle is easy enough. Every consonant (spelling matters, not pronunciation) is doubled, and an o is inserted in-between. Vowels are left intact. It is quite possible to render the Rövarspråket version of an English word as well as a Swedish, e.g.:
(or less intelligbly written without the hyphens) that syllable chain would mean stubborn. Needless to say, the code is not very useful in written form, but it can be tough when spoken by a trained (and thus quick) user. On the other hand, for an untrained speaker, a word or phrase can often be something of a tongue-twister or a shibboleth.
Today, the books (and subsequent films) are so well-known in Sweden, and also in Norway, that the language has become integrated in the culture of schoolchildren. Most Scandinavians are familiar with it.