Translating Lilypond

[address@hidden]

I thinking about translating Lilypond to Swedish.
I have downloaded the last Swedish translation file: 
lilypond-2.15.37.1.sv.po (which is for Lilypond 1.7.29...)
and also the current one: lilypond-2.15.37.1.pot

In the .pot file there are word that shouldn't be translated. E. g. 
\\header { key = concat + with + operator }

Is there a list of words that shouldn't be translated?

// Anders

--
English isn't my first language.
So any error or strangeness is due to the translation.
Please correct my English so that I may become better.