describes an option with an associated value
This option must not appear more than once in the options list.
| std::MULTI_VALUED_OPTION | describes an option with an associated list of values |
| std::MANDATORY_PARAMETER | describes a mandatory parameter |
| std::OPTIONAL_PARAMETER | describes an optional parameter |
| std::SOME_PARAMETERS | describes list of zero or more parameters |
| std::MANY_PARAMETERS | describes list of one or more parameters |