%@% IF pass1
%@% ELSE
%%% src_install
Dataword \Arg{rootprefix} means that the project uses root directory \File{/}
along with \File{/usr} and several essential packages are installed to root directory.
When the system is merged to \File{/usr}, this word is absent in configuration.

The string with \Prog{ause} command chooses the first block in case of presence of \Arg{rootprefix}.
%@% END-IF
