Most of the content is in Translation:General_Information.
A special section on translation testing should be written. It should include info on KeyID builds.
Are theese toolbar icons? ooo_custom_images/industrial/res/commandimagelist/de Localisation of other images
Localization of Online Help requires one to localize images located in default_images/res and helpcontent styles in helpcontent2/source/auxiliary (ref: Localisation in the help system