The Hyper Text Coffee Pot Control Protocol (HTCPCP for short) is a protocol for controlling, monitoring, and diagnosing coffee pots.

HTCPCP is specified in the jocular RFC

Request for Comments

In computer network engineering, a Request for Comments is a memorandum published by the Internet Engineering Task Force describing methods, behaviors, research, or innovations applicable to the working of the Internet and Internet-connected systems.Through the Internet Society, engineers and...

 2324, published on 1 April 1998. Although the RFC describing the protocol is an April Fools' Day joke

April Fools' Day RFC

Almost every April Fools' Day since 1989, the Internet Engineering Task Force has published one or more humorous RFC documents, following in the path blazed by the June 1973 RFC 527 entitled ARPAWOCKY, which parodied Lewis Carroll's nonsense poem Jabberwocky...

, it specifies the protocol accurately enough for it to be a real, non-fictional protocol. The editor Emacs

Emacs

Emacs is a class of text editors, usually characterized by their extensibility. GNU Emacs has over 1,000 commands. It also allows the user to combine these commands into macros to automate work.Development began in the mid-1970s and continues actively...

 actually includes a fully functional implementation of it, and a number of bug reports exist complaining about Mozilla's

Mozilla

Mozilla is a term used in a number of ways in relation to the Mozilla.org project and the Mozilla Foundation, their defunct commercial predecessor Netscape Communications Corporation, and their related application software....

 lack of support for the protocol. Ten years after the publication of HTCPCP, the fictional Web-Controlled Coffee Consortium (WC3) published a first draft of "HTCPCP Vocabulary in RDF

Resource Description Framework

The Resource Description Framework is a family of World Wide Web Consortium specifications originally designed as a metadata data model...

" in analogy of the World Wide Web Consortium

World Wide Web Consortium

The World Wide Web Consortium is the main international standards organization for the World Wide Web .Founded and headed by Tim Berners-Lee, the consortium is made up of member organizations which maintain full-time staff for the purpose of working together in the development of standards for the...

's (W3C) "HTTP Vocabulary in RDF".

Commands and replies

HTCPCP is an extension of HTTP

Hypertext Transfer Protocol

The Hypertext Transfer Protocol is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web....

. HTCPCP requests are identified with the URI

Uniform Resource Identifier

In computing, a uniform resource identifier is a string of characters used to identify a name or a resource on the Internet. Such identification enables interaction with representations of the resource over a network using specific protocols...

 scheme coffee: (or the corresponding word in any other of the 29 listed languages) and contain several additions to the HTTP methods:

BREW or POST	Causes the HTCPCP server to brew coffee Coffee Coffee is a brewed beverage with a dark,init brooo acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia,...
GET	Retrieves coffee from the HTCPCP server
PROPFIND	Finds out metadata about the coffee
WHEN	Says "when", causing the HTCPCP server to stop pouring milk Milk Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...  into the coffee (if applicable)

It also defines two error responses:

406 Not Acceptable

The HTCPCP server is unable to brew coffee for some reason; the response should indicate a list of acceptable coffee types.

418 I'm a teapot

The HTCPCP server is a teapot Teapot A teapot is a vessel used for steeping tea leaves or a herbal mix in near-boiling water. Tea may be either in a tea bag or loose, in which case a tea strainer will be needed, either to hold the leaves as they steep or to catch the leaves inside the teapot when the tea is poured... ; the resulting entity may be short and stout I'm a Little Teapot "The Teapot Song" is a song describing the heating and pouring of a teapot or tea kettle. The song was originally written by George Harold Sanders and Clarence Z... . Demonstrations of this behaviour exist.