A Uniform Resource Identifier [RFC 2396] is the fundamental way to name or locate something in the World Wide Web. Formally, URIs represent the union of Uniform Resource Locators and Uniform Resource Names [RFC 2141].
The most general syntax for a URI is
Scheme ":" scheme-specific-part
If the scheme-specific-part starts with a double slash (“//”), the URI is called a “generic URI.” In this case, a specific substructure to the scheme-specific-part is implied as follows:
Scheme "://" authority path [ "?" query ]
Here square brackets surround the optional parts, italics indicate variables, and quoted text indicates fixed characters.
The scheme name is case independent and must start with a letter. The remainder of ...