Customizing the Request
Services like Slashdot's Backslash and RSS work because little input is needed—the same document is requested repeatedly. This is acceptable for retrieving documents from a file system on a remote server, but sometimes a little more customization is required. The client wants not only to request an XML document, but also to parameterize that document. For example, it might want to ask for headlines that include certain keywords or articles posted between two dates. The standard HTTP means of accomplishing this is to place the request parameters in a query string that is either attached to the end of the URL or included as the body of the HTTP request.
There are other ways to encode request parameters. For example, ...