2.3. AddDirective *global*
Adds a configuration directive that will be parsed for every catalog.cfg file. Accepts three parameters: the name of the directive, the name of the parser (if any), and the default value (if any). The following definition would add a directive "Foo," with parser "parse_bar," and a default value of "Hello, world!":
AddDirective Foo bar "Hello, world!"
If the parser is not defined, the directive value will be scalar and the same as what the user passes in the config file. If defined, the parser must be extant before it can be referenced, is always resident in Vend::Config, and begins with the string parse_.