Each parameter in a method call obeys the following syntax
[ (modifier) ] (mode) (type) (name)Where (mode) is one of in, out, or inout; (type) is any SIDL recognized type; and (name) is any non-reserved word4.2. The (modifier) is optional, and currently unimplemented. SIDL currently reserves the word copy for future use as an parameter modifier, and may add others in the future4.3.
For new users, the parameter's mode (e.g. in, out, or inout) is perhaps the most troublesome. On the surface, it's easy to explain that in parameters are passed into the code, out parameters come out, and inout parameters do both. However, there are some deeper issues that users need to be aware of.