URI schemes introduced before this date are not affected.

RFC 4395 describes the procedures for registering new URI schemes.

URI schemes should be registered with IANA, although non-registered schemes are used in practice.

User JavaScript is disabled for all URIs in the about or opera URI schemes as a security feature.

NetKernel supports a variety of URI schemes and introduces new ones specifically applicable to URI addressing within a software system.

The WebSocket protocol specification defines two new URI schemes, ws: and wss:, for unencrypted and encrypted connections respectively.

Dictionary, an application included with Mac OS X. Online dictionaries can be accessed by setting it as the helper for 'dict://' URI schemes.

PURLs are used to curate the URL resolution process, thus solving the problem of transitory URIs in location-based URI schemes like HTTP.

A namespace name also does not necessarily imply any of the semantics of URI schemes; a namespace name beginning with 'http:', for example, likely has nothing to do with the HTTP protocol.

HTTP resources are identified and located on the network by Uniform Resource Identifiers (URIs)-or, more specifically, Uniform Resource Locators (URLs)-using the or URI schemes.

URI schemes are frequently and incorrectly referred to as "protocols", or specifically as URI protocols or URL protocols, since most were originally designed to be used with a particular protocol, and often have the same name.

The official URI schemes registered with the IANA are as follows (note that "IETF Draft" in no way is a finalized specification and must not be treated so; refer to Section 2.2 of RFC 2026 for more details):

The standard for Magnet URIs was developed in 2002, partly as a "vendor- and project-neutral generalization" of the and URI schemes used by eDonkey2000 and Freenet, respectively, and attempts to follow official IETF URI standards as closely as possible.

The generic URI syntax mandates that new URI schemes that provide for the representation of character data in a URI must, in effect, represent characters from the unreserved set without translation, and should convert all other characters to bytes according to UTF-8, and then percent-encode those values.