The DECLARE command is valid only within a command procedure.

    The DECLARE command binds one or more actual parameters,
    specified on the command line following the execute procedure
    (@) command, to formal parameters (symbols) declared within a
    command procedure.

    Each p-name:p-kind pair specified by a DECLARE command binds one
    formal parameter to one actual parameter. Formal parameters are
    bound to actual parameters in the order in which the debugger
    processes the parameter declarations. If you specify several
    formal parameters on a single DECLARE command, the leftmost
    formal parameter is bound to the first actual parameter, the
    next formal parameter is bound to the second, and so on. If you
    use a DECLARE command in a loop, the formal parameter is bound
    to the first actual parameter on the first iteration of the loop;
    the same formal parameter is bound to the second actual parameter
    on the next iteration, and so on.

    Each parameter declaration acts like a DEFINE command: it
    associates a formal parameter with an address expression, a
    command, or a value expression in the current language, according
    to the parameter kind specified. The formal parameters themselves
    are consistent with those accepted by the DEFINE command and can
    in fact be deleted from the symbol table with the DELETE command.

    The %PARCNT built-in symbol, which can be used only within a
    command procedure, enables you to pass a variable number of
    parameters to a command procedure. The value of %PARCNT is the
    number of actual parameters passed to the command procedure.

    Related commands:

       @ (Execute Procedure)
       DEFINE
       DELETE