This is Perl module Keyword::Boolean. INSTALLATION Keyword::Boolean installation is straightforward. If your CPAN shell is set up, you should just be able to do $ cpan Keyword::Boolean Download it, unpack it, then build it as per the usual: $ perl Makefile.PL $ make && make test Then install it: $ make install DOCUMENTATION Keyword::Boolean documentation is available as in POD. So you can do: $ perldoc Keyword::Boolean to read the documentation online with your favorite pager. Goro Fuji (gfx)