> There was a funny guide circulating a few years ago about "Euro-English" used in the European Union and it's institutions, that was completely incomprehensible to a native speaker.

A lot of it is just (1) use of French loanwords to refer to EU-specific concepts (acquis is arguably the most famous), (2) use of genuine but rare English words – for example "subsidiarity", a word few English-speakers know, but the EU loves – but it isn't exclusive to the EU, Catholic theologians love it too (there is a whole section devoted to it in the Catholic Catechism), (3) the kind of common linguistic errors (false cognates, etc) which French speakers (and to a lesser degree, speakers of other EU languages) make when speaking English.

There are also some cases where it is hard to say if what is happening is (1) or (3), for example the use of the word "cabinet" (pronounced the French way) to refer to the office staff of a senior official