Recommended 

hh: 

When the file selection dialog box is used to choose an existing directory (for example, to install a set of files into the chosen directory) or to specify a new directory, the command button should be given an appropriate label, such as Install, Choose, Create, or OK. If this button is activated while the appropriate directory is selected in the contents list, the directory is utilized by the application and the file selection box is dismissed. 

Required 

hi: 

When the file selection dialog box is used to choose an existing directory, there must also be an additional button, labeled Update, that is enabled whenever a directory is selected in the contents list, and opens the directory. This Update button is the default action. 

Optional 

hk: 

When the file selection dialog box is used to choose an existing file, files are shown in the contents list but they are all disabled. Double-clicking BSelect on a disabled file name has no effect.