Resources are identified by URIs:

Note: For the syntax for specifying parameters in URIs, see Variables and values.

Scheme name

Hierarchical identifiers

  • Authority is mandatory.

  • Authority has the following generic syntax: 

    <host name>[:<port number>]

  • Host name is separated from the port number with a colon ( : ).

Host name
  • Host name is mandatory.

  • Host name can be defined by the domain name (DNS domain).

  • Host name can be defined by an IP.

Port number
  • Port number is optional.

  • Port number is a 16-bit integer.

  • Port number is separated from host name by a colon (:).


  • Path is mandatory.

  • Path has the following generic syntax: 

    [[/<Segment Name>]]

  • Path represents a sequence of segments.

  • Segments are separated by a slash (/).

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  • Parameters contain a name and a value.

  • Parameter names and parameter values are separated by an equals sign (=)

  • Parameter names are case sensitive.

  • Parameter values are generally not case sensitive.

The following clauses can be appended to a request URI:

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See also: