The Protocol object handles two types of callback functions: one for a client application and one for a server application. This means that you can register not only any type of protocol clients but also their server counterparts. Whether it is a client module or a server module, a protocol module is identified by an access scheme which is identical to the access scheme known from the URL syntax, for example
http://www.w3.org ftp://ftp.w3.org etc.The User's Guide describes in detail how you can set up the protocol modules in your application.