Frankly, I am not sure this is so bad idea. E.g. Excel took the opposite approach - and localized all function names too. So a SUM() became SOMME() in French. Writing Excel macros is now a horrific mess because one macro that works on your PC doesn't work on colleague's who happens to have a French version! Oh and don't ever try to follow some online tutorial - you would need a dictionary at hand and translate all the function names first. Given that GMail's filters and search are on a similar level as the Excel macros, I would argue that it does make sense to keep those identifiers non-localized. Or accept both variants (which would likely be a huge mess to deal with internally).