Redmine

... changes underscore to underscores (plural form).
Native speakers told me they'd rather not use the plural form, reasoning that it's not a french word but a foreign one and as such, may stay in its native form.

The french academy say that foreign words take a plural french form when this words are commonly used.

Notice about this rule : http://www.academie-francaise.fr/niky-orange
Plural form of underscore : http://fr.wiktionary.org/wiki/underscores

Or maybe we can replace underscore by "tiret bas / tirets bas" : http://fr.wikipedia.org/wiki/Tiret_bas

Alexis Blandin wrote:

The french academy say that foreign words take a plural french form when this words are commonly used.

Oh... Well, I only asked my wife and a friend of mine, both said they'd not add a plural "s"...

les mots d’origine étrangère prennent les marques normales du français (accents, pluriels) quand ils sont intégrés à notre langue.

Tranlsation (my own):

Foreign words, if integrated in everyday language, take the normal forms of the french language (accents, plurals).

==> patch should be merged