The Help pages for V7 PlanarUnion, PlanarDifference and PlanarIntersection only exist in English. If one tries to access them when running Rhino in German or French by starting the command and then pressing F1, you get something like this:
@Helvetosaur
Thanks for reporting this. The missing topics in the localized versions will be added when @translators complete a new round of updating the project. Rhino Help is a huge project. It is difficult to keep all localized topics up-to-date while they have several other localization works (UI, enews, website, wiki…) on going.
Yes, I know.
Starting with Rhino 5 (and 6, 7, 8) the translation into Russian is Terrible. Probably, the translations were carried out by people who did not know Russian well. Some of the translation was done incorrectly or confusingly.