Translations:Handbook:Parts/Working/USE/10/en

Take a look at a specific example: the  keyword. If this keyword is not in the USE variable, all packages that have optional KDE support will be compiled without KDE support. All packages that have an optional KDE dependency will be installed without installing the KDE libraries (as dependency). When the kde keyword is defined, then those packages will be compiled with KDE support, and the KDE libraries will be installed as dependency.