6.1.2.2 Argument Matching and Invocation

Once the destination object is found, if it is callable and not a class, the Publisher handler will get a list of arguments that the object expects. This list is compared with names of fields from HTML form data submitted by the client via POST or GET. Values of fields whose names match the names of callable object arguments will be passed as strings.

If the destination is not callable or is a class, then its string representation is returned to the client.