URIschemes are sometimes erroneously referred to as "protocols", or specifically as URIprotocols or URL protocols, since most were originally designed to be used with a particular protocol, and often have the same name.
Today, URIs with that scheme are also used for other purposes, such as RDF resource identifiers and XML namespaces, that are not related to the protocol.
URIschemes should be registered with IANA, although many non-registered schemes are used in practice.
If the given URI's fragment component is defined, its path component is empty, and its scheme, authority, and query components are undefined, then a URI with the given fragment but with all other components equal to those of this URI is returned.
A new URI is constructed with this URI'sscheme and the given URI's query and fragment components.
Otherwise a new relative hierarchical URI is constructed with query and fragment components taken from the given URI and with a path component computed by removing this URI's path from the beginning of the given URI's path.
URI producing applications should percent-encode data octets that correspond to characters in the reserved set unless these characters are specifically allowed by the URIscheme to represent data in that component.
When a new URIscheme defines a component that represents textual data consisting of characters from the Universal Character Set [UCS], the data should first be encoded as octets according to the UTF-8 character encoding [STD63]; then only those octets that do not correspond to characters in the unreserved set should be percent-encoded.
URIscheme names, as defined by in Section 3.1, form a registered namespace that is managed by IANA according to the procedures defined in [BCP35].
The info URIscheme was developed within the library and publishing communities (specifically, in conjunction with the development of the NISO OpenURL standard; more below) because of the need for URIs as pure identifiers, that is, to identify (not retrieve, dereference, locate, name, or any of those other things that URIs do).
Note that we have described a URI in general as "a character string beginning with a scheme name followed by a colon (':') and the remainder of the uri is scheme specific".
The namespace specific part of an 'info' URI may be a simple identifier as in the 'lccn' and 'doi' cases, or it may be further structured (and even use further slashes as delimiters) as in the case for SRW and NetRef 'info' URIs.
URIs that identify in relation to the end-user's local context should only be used when the context itself is a defining aspect of the resource, such as when an on-line help manual refers to a file on the end- user's file system (e.g., "file:///etc/hosts").
URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ] hier-part = "//" authority path-abempty / path-absolute / path-rootless / path-empty The scheme and path components are required, though the path may be empty (no characters).
URIscheme specifications must define their own syntax so that all strings matching their scheme-specific syntax will also match the grammar, as described in Section 4.3.
The "feed" URIscheme is not limited to identifying the aforementioned XML-based file formats but can and should be used to identify other network retrievable resources used to syndicate information from a particular news source.
The feedURI syntax is primarily dependent on the scheme used to retrieve the data feed over the network.
If the "feed" URI string begins with the string 'feed://' then it MUST be followed by an authority with optional path and query string with the scheme for the URI for accessing the data feed being inferred as the "http" scheme.
About "info" URIs - Frequently Asked Questions(Site not responding. Last check: 2007-11-05)
As such, the URI syntax is a federated and extensible naming system wherein each scheme's specification may further restrict the syntax and semantics of identifiers using that scheme.
The INFO URIscheme was developed from within the library and publishing communities to expedite the referencing by URIs of information assets that have identifiers in public namespaces but have no representation within the URI allocation.
INFO URIs are conformant to the general syntax requirements of URIs as laid out in RFC 3986 and as such are readily parseable and recognizable as legitimate URI strings.
This scheme is similar to the mailto URIscheme [4].
Reserved characters are special characters used as delimiters withing URIs and whose usage is limited to their reserved purpose as defined in RFC 3986 or a specific URIscheme.
The mailto URIscheme is described in RFC 2368: http://www.ietf.org/rfc/rfc2368.txt.
A *retired index* of WWW Addressing Schemes (via CobWeb/3.1 planetlab2.isi.jhu.edu)(Site not responding. Last check: 2007-11-05)
This was an attempt to index URIschemes and their specifications, whether they were registered or not.
A new naming scheme may be introduced by defining a mapping onto a conforming URL syntax, using a new prefix.
It is recommended that those proposing a new scheme demonstrate its utility and operability by the provision of a gateway which will provide images of objects in the new scheme for clients using an existing protocol.
Tag URIs (also known as "tags") are designed to be unique across space and time while being tractable to humans.
The component "specific" is the name-space-specific part of the URI: it is a string of URI characters (see restrictions in syntax specification) chosen by the minter of the URI.
Tag URIs may optionally end in a fragment identifier, in accordance with the general syntax of RFC 3986 [1].
The MagnetLink.org website collects resources of interest to users of MAGNETURIs, including the helpful introductory Kazaa Magnet CDK (Content Distribution Kit).
MagnetHandler is a project to create a "MAGNET router tool" which will allow multiple MAGNET applications, which each handle certain kinds of MAGNETURIs, to coexist.
Example Page of MAGNETURIs, with Javascript code to catch clicks on these links and automatically probe for any local apps which can do interesting things with the URIs.
