I'm not sure if you're trying to add defaults to your report parameters or your SP parameters.

In case that you want defaults to your SP parameters, you have two options and I believe that you found one.

First option:

CREATE PROCEDURE MyProcedure(

@Param1 int = 5,

@Param2 varchar(50) = 'Some default'

)

AS ...

The second option is to default the values to NULL and assign values dinamically.

CREATE PROCEDURE MyProcedure(

@Param1 int = NULL,

@Param2 varchar(50) = NULL

)

AS

BEGIN

IF @Param1 IS NULL AND @Param2 IS NULL

BEGIN

--Code to assign default values

END

--Code for SP

END