default-help? | A boolean value controlling if a --help option is added. |
allow-abbrev? | A boolean value controlling if abbreviations are allowed for options. |
program-name | An optional program name, or it will be inferred from the script or launched binary name. |
program-prolog | Some text to include in the help display before the options. |
program-epilog | Some text to include in the help display after the options. |