You can define a symbol to invoke the Relational Data
    Manipulation Language (RDML) preprocessor. For example:

    $ RDML :== $RDML
    $ RDML
    _Source file: SAL_HISTORY.RC

    A more convenient method is to define symbols. For example:

    $ RDMLC    :== $RDML/C
    $ RDMLPAS  :== $RDML/PASCAL
    $!
    $ RDMLC SAL_HISTORY.RC

    See the RDML Help module that is available from DCL level for
    details.