While reviewing Edits I came across this edit to an answer which was written in both English and Spanish: http://stackoverflow.com/posts/6961084/revisions
The only thing that the Edit did was remove the non-english portion of the answer. The editor did not indicate that the non-english portion was inaccurate, just that it was being removed simply for being non-english.
I have search around meta and found many questions pertaining to non-english posts:
and the official policy from here:
Throughout many of these the consensus seems to be largely that we want the content to be in English. But I don't see anywhere that explicitly states that Non-English content is unacceptable even if an English version of the same content was supplied by the same person as is the case with the answer above.
So my question: If we find content that is posted in multiple languages should all of the Non-English content be removed just because it isn't English?
Personally I would lean towards leaving the non-english part there as long as both languages are given, the chance that it may better help someone in the future and it certainly does not hinder anyone else (since both languages were given) is enough that I feel it should be left there. I am interested to know if this is covered by the official language policy though.