Passing composite types to plpgsql functions

/doc/html/plpgsql-description.html states that:

"Parameters to a function can be composite types (complete table rows). In
that case, the corresponding identifier $n will be a rowtype, but it must be
aliased using the ALIAS command described above."

What syntax do I need in my function declaration to receive a parameter of
something%ROWTYPE ?

Thanks,
-Jeff