If you are developing a Web application on a computer that is behind a firewall, and your application will consume Web services from outside the firewall, you must include the address and port of your network's proxy server in the URL. Ask your network administrator to furnish this part of the URL path. For more information, see "The proxy settings on this computer are not configured correctly for Web discovery" in the Visual Studio 2005 SDK.

When you open a project for editing that includes a Web reference, a local proxy file for the Web service consumed runs in a process of Devenv.exe started by a trusted user, yourself. Opening projects or components in the integrated development environment (IDE) can execute code on your local computer. For more information, see Overview of Web Application Security Threats and Code Access Security.

By default, Web references are assigned a namespace that corresponds to their server name. You can change this value and enter a custom namespace name. There are some limitations on acceptable namespace names. For more information about characters that are not allowed in a Web reference name, see Add Web Reference Dialog Box. Visual Web Developer creates a namespace based on the Web reference name by building a nested folder hierarchy. Inside the innermost folder, a .wsdl file that references the Web service is created, along with supporting files, such as discovery (.disco and .discomap) files, that include information about where the Web service is located.