Request for Comments in the context of List of HTTP status codes

Portable Network Graphics (PNG, officially pronounced /pɪŋ/ PING, colloquially pronounced /ˌpiːɛnˈdʒiː/ PEE-en-JEE) is a raster-graphics file format that supports lossless data compression. PNG was developed as an improved, non-patented replacement for Graphics Interchange Format (GIF).

PNG supports palette-based images (with palettes of 24-bit RGB or 32-bit RGBA colors), grayscale images (with or without an alpha channel for transparency), and full-color non-palette-based RGB or RGBA images. The PNG working group designed the format for transferring images on the Internet, not for professional-quality print graphics; therefore, non-RGB color spaces such as CMYK are not supported. A PNG file contains a single image in an extensible structure of chunks, encoding the basic pixels and other information such as textual comments and integrity checks documented in RFC 2083.

In computer network engineering, an Internet Standard is a normative specification of a technology or methodology applicable to the Internet. Internet Standards are created and published by the Internet Engineering Task Force (IETF). They allow interoperation of hardware and software from different sources which allows internets to function. As the Internet became global, Internet Standards became the lingua franca of worldwide communications.

Engineering contributions to the IETF start as an Internet Draft, may be promoted to a Request for Comments, and may eventually become an Internet Standard.

Internet Standard (often abbreviated STD) is the highest maturity level in the Internet Engineering Task Force (IETF) standards track for Internet protocol specifications. Internet Standards are published as one or more Request for Comments (RFC) documents and are additionally assigned an STD number that identifies the standard as a whole (as distinct from the RFC document number).

The Internet Standards Process is defined in a series of IETF Best Current Practice documents, including RFC 2026 and RFC 6410. Not all RFCs are Internet Standards; RFCs may also be informational, experimental, or otherwise outside the standards track.

Stephen D. Crocker (born October 15, 1944) is an American Internet pioneer. In 1969, he created the ARPA "Network Working Group" and the Request for Comments series. He served as chair of the board of the Internet Corporation for Assigned Names and Numbers (ICANN) from 2011 through 2017.

mailto is a Uniform Resource Identifier (URI) scheme for email addresses. It is used to produce hyperlinks on websites that allow users to send an email to a specific address directly from an HTML document, without having to copy and enter it into an email client.

It was originally defined by Request for Comments (RFC) 1738 in December 1994, expanded by RFC 2368 in July 1998, and refined by RFC 6068 in October 2010.