If you use the PARAMETER COLONS clause, all parameter names must
    begin with a colon (:).  This rule applies to both declarations
    and references of module language procedure parameters. If you do
    not use this clause, no parameter name can begin with a colon.

    The current default behavior is no colons are used. However, this
    default is deprecated syntax. In the future, colons will be the
    default because it allows processing of ANSI-standard modules.

    Use the PARAMETER COLONS clause, rather than the ANSI_PARAMETERS
    qualifier, because the qualifier will be deprecated in a future
    release.