* '''<tt>D</tt>''' - Consider the entire dependency tree of packages when looking for updates. In other words, do a '''deep''' update.
* '''<tt>N</tt>''' - Update any packages who have changed ('''new''') USE settings.
Of course, sometimes we want to install a package but not add it the world file. This is often done because you only want the package installed temproarily or because you know the package in question is a dependnecy of another package. If this behavior is desired, you call emerge like this: