Uniform Resource Identifier - Wikipedia

Uniform Resource Identifier - Wikipedia
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(Redirected from
URI scheme
String used to identify a name of a web or internet resource
"URI" redirects here. For other uses, see
URI (disambiguation)
Not to be confused with
URL
Uniform Resource Identifier
Abbreviation
URI
Native name
RFC
3986
Status
Active
Organization
Internet Engineering Task Force
Authors
Tim Berners-Lee
Roy Thomas Fielding
Larry Masinter
Domain
World Wide Web
Website
datatracker
.ietf
.org
/doc
/html
/rfc3986
#section-1
.1
Uniform Resource Identifier
URI
), formerly
Universal Resource Identifier
, is a unique sequence of characters that identifies an abstract or physical resource,
: 1
such as resources on a
webpage
email address
, phone number,
: 7
books, real-world objects such as people and places, and concepts. In particular, the resource need not be retrievable via the Internet, or any computer network.
: 5
URIs which provide a means of locating and
retrieving
information resources on a
network
(either on the Internet or on another
private network
, such as a
computer file system
or an
Intranet
) are
Uniform Resource Locators
(URLs). Therefore, URLs are a subset of URIs, i.e. every URL is a URI (and not necessarily the other way around).
: 7
Other URIs provide only a unique name, without a means of locating or retrieving the resource or information about it; these are
Uniform Resource Names
(URNs). The web technologies that use URIs are not limited to
web browsers
History
edit
Conception
edit
URIs and URLs have a shared history. In 1990,
Tim Berners-Lee's
proposals for
hypertext
implicitly introduced the idea of a URL as a short string representing a resource that is the target of a
hyperlink
At the time, people referred to it as a "hypertext name"
or "document name".
Over the next three and a half years, as the
World Wide Web's
core technologies of
HTML
HTTP
, and
web browsers
developed, a need to distinguish a string that provided an address for a resource from a string that merely named a resource emerged. Although not yet formally defined, the term
Uniform Resource Locator
came to represent the former, and the more contentious
Uniform Resource Name
came to represent the latter. In July 1992 Berners-Lee's report on the
Internet Engineering Task Force
(IETF) "UDI (Universal Document Identifiers)
BOF
" mentions URLs (as Uniform Resource Locators), URNs (originally, as Unique Resource Numbers), and the need to charter a new working group.
In November 1992 the IETF "URI Working Group" met for the first time.
During the debate over defining URLs and URNs, it became evident that the concepts embodied by the two terms were merely aspects of the fundamental, overarching, notion of resource
identification
. In June 1994, the IETF published
RFC
1630
, Berners-Lee's first
Request for Comments
that acknowledged the existence of URLs and URNs. Most importantly, it defined a formal syntax for
Universal Resource Identifiers
(i.e. URL-like strings whose precise syntaxes and semantics depended on their schemes). It also attempted to summarize the syntaxes of URL schemes in use at the time. It acknowledged –
but did not standardize
—the existence of relative URLs and fragment identifiers.
Refinement
edit
In December 1994,
RFC
1738
formally defined relative and absolute URLs, refined the general URL syntax, defined how to resolve relative URLs to absolute form, and better enumerated the URL schemes then in use. The agreed definition and syntax of URNs had to wait until the publication of IETF
RFC
2141
in May 1997.
The publication of IETF
RFC
2396
in August 1998 saw the URI syntax become a separate specification
and most of the parts of RFCs 1630 and 1738 relating to URIs and URLs in general were revised and expanded by the IETF. The new RFC changed the meaning of
in
URI
from "Universal" to "Uniform."
In December 1999,
RFC
2732
10
provided a minor update to RFC 2396, allowing URIs to accommodate
IPv6
addresses. A number of shortcomings discovered in the two specifications led to a community effort, coordinated by RFC 2396 co-author
Roy Fielding
, that culminated in the publication of IETF
RFC
3986
in January 2005. While obsoleting the prior standard, it did not render the details of existing URL schemes obsolete; RFC 1738 continues to govern such schemes except where otherwise superseded. IETF
RFC
2616
11
for example, refines the
http
scheme. Simultaneously, the IETF published the content of RFC 3986 as the full standard STD 66, reflecting the establishment of the URI generic syntax as an official Internet protocol.
In 2001, the
World Wide Web Consortium's
(W3C) Technical Architecture Group (TAG) published a guide to
best practices
and canonical URIs for publishing multiple versions of a given resource.
12
For example, content might differ by language or by size to adjust for capacity or settings of the device used to access that content.
In August 2002, IETF
RFC
3305
13
pointed out that the term "URL" had, despite widespread public use, faded into near obsolescence, and serves only as a reminder that some URIs act as addresses by having schemes implying network accessibility, regardless of any such actual use. As URI-based standards such as
Resource Description Framework
make evident, resource identification need not suggest the retrieval of resource representations over the Internet, nor need they imply network-based resources at all.
The
Semantic Web
uses the HTTP URI scheme to identify both documents and concepts for practical uses, a distinction which has caused confusion as to how to distinguish the two. The
TAG
published an e-mail in 2005 with a solution of the problem, which became known as the
httpRange-14 resolution
14
The W3C subsequently published an Interest Group Note titled "Cool URIs for the Semantic Web", which explained the use of
content negotiation
and the
HTTP 303
response code for redirections in more detail.
15
Design
edit
URLs and URNs
edit
Uniform Resource Name
(URN) is a URI that identifies a resource by name in a particular namespace. A URN may be used to talk about a resource without implying its location or how to access it. For example, in the
International Standard Book Number
(ISBN) system,
ISBN 0-486-27557-4
identifies a specific edition of the
William Shakespeare
play
Romeo and Juliet
. The URN for that edition would be
urn:isbn:0-486-27557-4
. However, it gives no information as to where to find a copy of that book.
Uniform Resource Locator
(URL) is a URI that specifies the means of acting upon or obtaining the representation of a resource, i.e. specifying both its primary access mechanism and network location. For example, the URL
refers to a resource identified as
/wiki/Main_Page
, whose representation is obtainable via the
Hypertext Transfer Protocol
http:
) from a network host whose
domain name
is
example.org
. (In this case, HTTP usually implies it to be in the form of
HTML
and related code. In practice, that is not necessarily the case, as HTTP allows specifying arbitrary formats in its header.)
A URN is analogous to a person's name, while a URL is analogous to their street address. In other words, a URN identifies an item and a URL provides a method for finding it.
Technical publications, especially standards produced by the IETF and by the W3C, normally reflect a view outlined in a
W3C Recommendation
of 30 July 2001, which acknowledges the precedence of the term URI rather than endorsing any formal subdivision into URL and URN.
URL is a useful but informal concept: a URL is a type of URI that identifies a resource via a representation of its primary access mechanism (e.g., its network "location"), rather than by some other attributes it may have.
16
As such, a URL is simply a URI that happens to point to a resource over a network.
13
However, in non-technical contexts and in software for the World Wide Web, the term "URL" remains widely used. Additionally, the term "web address" (which has no formal definition) often occurs in non-technical publications as a synonym for a URI that uses the
http
or
https
schemes. Such assumptions can lead to confusion, for example, in the case of XML namespaces that have a
visual similarity to resolvable URIs
Specifications produced by the
WHATWG
prefer
URL
over
URI
, and so newer HTML5 APIs use
URL
over
URI
17
Standardize on the term URL. URI and IRI [Internationalized Resource Identifier] are just confusing. In practice a single algorithm is used for both so keeping them distinct is not helping anyone. URL also easily wins the search result popularity contest.
18
While most URI schemes were originally designed to be used with a particular
protocol
, and often have the same name, they are semantically different from protocols. For example, the scheme
http
is generally used for interacting with
web resources
using HTTP, but the scheme
file
has no protocol.
Syntax
edit
See also:
List of URI schemes
A URI has a scheme that refers to a specification for assigning identifiers within that scheme. 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 URI generic syntax is a superset of the syntax of all URI schemes. It was first defined in
RFC
2396
, published in August 1998,
and finalized in
RFC
3986
, published in January 2005.
19
A URI is composed from an allowed set of
ASCII
characters consisting of
reserved characters
(gen-delims:
, and
; sub-delims:
, and
),
: 13–14
unreserved characters (
uppercase and lowercase letters
decimal digits
, and
),
: 13–14
and the character
: 12
Syntax components and subcomponents are separated by
delimiters
from the reserved characters (only from generic reserved characters for components) and define
identifying data
represented as unreserved characters, reserved characters that do not act as delimiters in the component and subcomponent respectively,
: §2
and
percent-encodings
when the corresponding character is outside the allowed set or is being used as a delimiter of, or within, the component. A percent-encoding of an identifying data
octet
is a sequence of three characters, consisting of the character
followed by the two hexadecimal digits representing that octet's numeric value.
: §2.1
The URI generic syntax consists of five
components
organized hierarchically in order of decreasing significance from left to right:
: §3
URI = scheme ":" ["//" authority] path ["?" query] ["#" fragment]
A component is
undefined
if it has an associated delimiter and the delimiter does not appear in the URI; the scheme and path components are always defined.
: §5.2.1
A component is
empty
if it has no characters; the scheme component is always non-empty.
: §3
The authority component consists of
subcomponents
authority = [userinfo "@"] host [":" port]
This is represented in a
syntax diagram
as:
The URI comprises:
A non-empty
scheme
component followed by a colon (
), consisting of a sequence of characters beginning with a letter and followed by any combination of letters, digits, plus (
), period (
), or hyphen (
). Although schemes are case-insensitive, the canonical form is lowercase and documents that specify schemes must do so with lowercase letters. Examples of popular schemes include
http
https
ftp
mailto
file
data
and
irc
. URI schemes should be registered with the
Internet Assigned Numbers Authority (IANA)
, although non-registered schemes are used in practice.
20
An optional
authority
component preceded by two slashes (
//
), comprising:
An optional
userinfo
subcomponent followed by an at symbol (
), that may consist of a
user name
and an optional
password
preceded by a colon (
). Use of the format
username:password
in the userinfo subcomponent is deprecated for security reasons. Applications should not render as clear text any data after the first colon (
) found within a userinfo subcomponent unless the data after the colon is the empty string (indicating no password).
host
subcomponent, consisting of either a registered name (including but not limited to a
hostname
) or an
IP address
IPv4
addresses must be in
dot-decimal notation
, and
IPv6
addresses must be enclosed in brackets (
[]
).
: §3.2.2
An optional
port
subcomponent preceded by a colon (
), consisting of decimal digits.
path
component, consisting of a sequence of path segments separated by a slash (
). A path is always defined for a URI, though the defined path may be empty (zero length). A segment may also be empty, resulting in two consecutive slashes (
//
) in the path component. A path component may resemble or map exactly to a
file system path
but does not always imply a relation to one. If an authority component is defined, then the path component must either be empty or begin with a slash (
). If an authority component is undefined, then the path cannot begin with an empty segment—that is, with two slashes (
//
)—since the following characters would be interpreted as an authority component.
: §3.3
By convention, in
http
and
https
URIs, the last part of a
path
is named
pathinfo
and it is optional. It is composed by zero or more path segments that do not refer to an existing physical resource name (e.g. a file, an internal module program or an executable program) but to a logical part (e.g. a command or a qualifier part) that has to be passed separately to the first part of the path that identifies an executable module or program managed by a
web server
; this is often used to select dynamic content (a document, etc.) or to tailor it as requested (see also:
CGI
and PATH_INFO, etc.).
Example:
URI:
"http://www.example.com/questions/3456/my-document"
where:
"/questions"
is the first part of the
path
(an executable module or program) and
"/3456/my-document"
is the second part of the
path
named
pathinfo
, which is passed to the executable module or program named
"/questions"
to select the requested document.
An
http
or
https
URI containing a
pathinfo
part without a
query
part may also be referred to as a '
clean URL
,' whose last part may be a '
slug
.'
Query delimiter
Example
Ampersand (
key1=value1&key2=value2
Semicolon (
key1=value1;key2=value2
An optional
query
component preceded by a question mark (
), consisting of a
query string
of non-hierarchical data. Its syntax is not well defined, but by convention is most often a sequence of
attribute–value pairs
separated by a
delimiter
An optional
fragment
component preceded by a
hash
). The fragment contains a
fragment identifier
providing direction to a secondary resource, such as a section heading in an article identified by the remainder of the URI. When the primary resource is an
HTML
document, the fragment is often an
id
attribute
of a specific element, and web browsers will scroll this element into view.
The scheme- or implementation-specific reserved character
may be used in the scheme, userinfo, host, path, query, and fragment, and the scheme- or implementation-specific reserved characters
, and
may be used in the userinfo, host, path, query, and fragment. Additionally, the generic reserved character
may be used in the userinfo, path, query and fragment, the generic reserved characters
and
may be used in the path, query and fragment, and the generic reserved character
may be used in the query and fragment.
: §A
Example URIs
edit
The following figure displays example URIs and their component parts.
DOIs (
digital object identifiers
) fit within the
Handle System
and fit within the URI system,
as facilitated by appropriate syntax
URI references
edit
URI reference
is either a URI or a
relative reference
when it does not begin with a scheme component followed by a colon (
).
: §4.1
A path segment that contains a colon character (e.g.,
foo:bar
) cannot be used as the first path segment of a relative reference if its path component does not begin with a slash (
), as it would be mistaken for a scheme component. Such a path segment must be preceded by a dot path segment (e.g.,
./foo:bar
).
: §4.2
Web document
markup languages
frequently use URI references to point to other resources, such as external documents or specific portions of the same logical document:
: §4.4
in
HTML
, the value of the
src
attribute of the
img
element provides a URI reference, as does the value of the
href
attribute of the
or
link
element;
in
XML
, the
system identifier
appearing after the
SYSTEM
keyword in a
DTD
is a fragmentless URI reference;
in
XSLT
, the value of the
href
attribute of the
xsl:import
element/instruction is a URI reference; likewise the first argument to the
document()
function.
//example.com/path/resource.txt
/path/resource.txt
path/resource.txt
../resource.txt
./resource.txt
resource.txt
#fragment
Resolution
edit
Resolving
a URI reference against a
base URI
results in a
target URI
. This implies that the base URI exists and is an
absolute URI
(a URI with no fragment component). The base URI can be obtained, in order of precedence, from:
: §5.1
the reference URI itself if it is a URI;
the content of the representation;
the entity encapsulating the representation;
the URI used for the actual retrieval of the representation;
the context of the application.
Within a representation with a well defined base URI of
a relative reference is resolved to its target URI as follows:
: §5.4
"g:h" -> "g:h"
"g" -> "http://a/b/c/g"
"./g" -> "http://a/b/c/g"
"g/" -> "http://a/b/c/g/"
"/g" -> "http://a/g"
"//g" -> "http://g"
"?y" -> "http://a/b/c/d;p?y"
"g?y" -> "http://a/b/c/g?y"
"#s" -> "http://a/b/c/d;p?q#s"
"g#s" -> "http://a/b/c/g#s"
"g?y#s" -> "http://a/b/c/g?y#s"
";x" -> "http://a/b/c/;x"
"g;x" -> "http://a/b/c/g;x"
"g;x?y#s" -> "http://a/b/c/g;x?y#s"
"" -> "http://a/b/c/d;p?q"
"." -> "http://a/b/c/"
"./" -> "http://a/b/c/"
".." -> "http://a/b/"
"../" -> "http://a/b/"
"../g" -> "http://a/b/g"
"../.." -> "http://a/"
"../../" -> "http://a/"
"../../g" -> "http://a/g"
URL munging
edit
URL munging is a technique by which a
command
is appended to a URL, usually at the end, after a "?"
token
. It is commonly used in
WebDAV
as a mechanism of adding functionality to
HTTP
. In a versioning system, for example, to add a "checkout" command to a URL, it is written as
. It has the advantage of both being easy for
CGI parsers
and also acts as an intermediary between HTTP and underlying resource, in this case.
24
Relation to XML namespaces
edit
In
XML
, a
namespace
is an abstract domain to which a collection of element and attribute names can be assigned. The namespace name is a character string which must adhere to the generic URI syntax.
25
However, the name is generally not considered to be a URI,
26
because the URI specification bases the decision not only on lexical components, but also on their intended use. A namespace name does not necessarily imply any of the semantics of URI schemes; for example, a namespace name beginning with
http:
may have no connotation to the use of the
HTTP
Originally, the namespace name could match the syntax of any non-empty URI reference, but the use of relative URI references was deprecated by the W3C.
27
A separate W3C specification for namespaces in XML 1.1 permits
Internationalized Resource Identifier
(IRI) references to serve as the basis for namespace names in addition to URI references.
28
See also
edit
CURIE
Linked data
Extensible Resource Identifier
Internationalized Resource Identifier
(IRI)
Internet resource locator
Persistent uniform resource locator
Uniform Naming Convention
Resource Directory Description Language
Universally unique identifier
List of URI schemes
Resource Description Framework
Notes
edit
A report published in 2002 by a joint W3C/IETF working group aimed to normalize the divergent views held within the IETF and W3C over the relationship between the various 'UR*' terms and standards. While not published as a full standard by either organization, it has become the basis for the above common understanding and has informed many standards since then.
For URIs relating to resources on the World Wide Web, some web browsers allow
.0
portions of dot-decimal notation to be dropped or raw integer IP addresses to be used.
21
Historic
RFC
1866
(obsoleted by
RFC
2854
22
) encourages CGI authors to support ';' in addition to '&'.
23
: §8.2.1
References
edit
T. Berners-Lee
R. Fielding
L. Masinter
(January 2005).
Uniform Resource Identifier (URI): Generic Syntax
. Network Working Group.
doi
10.17487/RFC3986
. STD 66.
RFC
3986
Internet Standard 66.
Obsoletes
RFC
2732
2396
and
1808
. Updated by
RFC
6874
7320
and
8820
. Updates
RFC
1738
Palmer, Sean.
"The Early History of HTML"
infomesh.net
. Retrieved
2020-12-06
"W3 Naming Schemes"
W3C
. 1992-02-24
. Retrieved
2020-12-06
"Proceedings of the Twenty-Fourth Internet Engineering Task Force"
(PDF)
IETF
. Corporation for National Research Initiatives. July 1992. p. 193
. Retrieved
2021-07-27
"Proceedings of the Twenty-Fifth Internet Engineering Task Force"
(PDF)
IETF
. Corporation for National Research Initiatives. November 1992. p. 501
. Retrieved
2021-07-27
Berners-Lee, Tim
(June 1994).
Universal Resource Identifiers in WWW: A Unifying Syntax for the Expression of Names and Addresses of Objects on the Network as used in the World-Wide Web
. Network Working Group.
doi
10.17487/RFC1630
RFC
1630
Informational.
T. Berners-Lee
L. Masinter
; M. McCahill (December 1994).
Uniform Resource Locators (URL)
. Network Working Group.
doi
10.17487/RFC1738
RFC
1738
Obsolete.
Obsoleted by
RFC
4248
and
4266
. Updated by
RFC
1808
2368
2396
3986
6196
6270
and
8089
R. Moats (May 1997).
P. Vixie
(ed.).
URN Syntax
IETF
Network Working Group.
doi
10.17487/RFC2141
RFC
2141
Proposed Standard.
Obsoleted by
RFC
8141
T. Berners-Lee
R. Fielding
L. Masinter
(August 1998).
Uniform Resource Identifiers (URI): Generic Syntax
. Network Working Group.
doi
10.17487/RFC2396
RFC
2396
Obsolete.
Obsoleted by
RFC
3986
. Updated by
RFC
2732
. Updates
RFC
1808
and
1738
R. Hinden;
B. Carpenter
L. Masinter
(December 1999).
Format for Literal IPv6 Addresses in URL's
. Network Working Group.
doi
10.17487/RFC2732
RFC
2732
Obsolete.
Obsoleted by
RFC
3986
R. Fielding
; J. Gettys; J. Mogul;
H. Frystyk
L. Masinter
; P. Leach;
T. Berners-Lee
(August 1999).
Hypertext Transfer Protocol -- HTTP/1.1
. Network Working Group.
doi
10.17487/RFC2616
RFC
2616
Obsolete.
Obsoleted by
RFC
7230
7231
7232
7233
7234
and
7235
. Obsoletes
RFC
2068
. Updated by
RFC
2817
5785
6266
and
6585
Raman, T.V. (2006-11-01).
"On Linking Alternative Representations To Enable Discovery And Publishing"
W3C
. Retrieved
2020-12-06
Mealling, Michael H.; Denenberg, Ray (August 2002).
Report from the Joint W3C/IETF URI Planning Interest Group: Uniform Resource Identifiers (URIs), URLs, and Uniform Resource Names (URNs): Clarifications and Recommendations
. Network Working Group.
doi
10.17487/RFC3305
RFC
3305
Informational.
Fielding, Roy (2005-06-18).
"[httpRange-14] Resolved"
W3C Public mailing list archives
. Retrieved
2020-12-06
Ayers, Danny; Völkel, Max (2008-12-03). Sauermann, Leo; Cyganiak, Richard (eds.).
"Cool URIs for the Semantic Web"
W3C
. Retrieved
2020-12-06
URI Planning Interest Group, W3C/IETF (September 2001).
"URIs, URLs, and URNs: Clarifications and Recommendations 1.0"
www.w3.org
. W3C/IETF
. Retrieved
2020-12-08
"6.3. URL APIs elsewhere"
URL Standard
. 2025-05-12.
"URL Standard: Goals"
Berners-Lee, Tim; Fielding, Roy T.; Masinter, Larry 2005
, p. 46; "9. Acknowledgements"
sfn error: no target: CITEREFBerners-Lee,_Tim;_Fielding,_Roy_T.;_Masinter,_Larry2005 (
help
Hansen, Tony; Hardie, Ted (June 2015). Thaler, Dave (ed.).
Guidelines and Registration Procedures for URI Schemes
Internet Engineering Task Force
doi
10.17487/RFC7595
ISSN
2070-1721
. BCP 35.
RFC
7595
Best Current Practice 35.
Updated by
RFC
8615
. Obsoletes
RFC
4395
Lawrence (2014)
D. Connolly
L. Masinter
(June 2000).
The 'text/html' Media Type
. Network Working Group.
doi
10.17487/RFC2854
RFC
2854
Informational / Legacy.
Obsoletes
RFC
1980
1867
1942
1866
and
2070
. Not endorsed by the
IETF
Berners-Lee, Tim
Connolly, Daniel W.
(November 1995).
Hypertext Markup Language - 2.0
. Network Working Group.
doi
10.17487/RFC1866
RFC
1866
Historic.
Obsoleted by
RFC
2854
Whitehead 1998
, p. 38.
Morrison (2006)
Harold (2004)
W3C (2009)
W3C (2006)
Works cited
edit
Bray, Tim
; Hollander, Dave; Layman, Andrew; Tobin, Richard, eds. (2006-08-16).
"Namespaces in XML 1.1 (Second Edition)"
World Wide Web Consortium
. 2.2 Use of URIs as Namespace Names
. Retrieved
2015-08-31
Bray, Tim
; Hollander, Dave; Layman, Andrew; Tobin, Richard; Thompson, Henry S., eds. (2009-12-08).
"Namespaces in XML 1.0 (Third Edition)"
World Wide Web Consortium
. 2.2 Use of URIs as Namespace Names
. Retrieved
2015-08-31
Harold, Elliotte Rusty
(2004).
XML 1.1 Bible
(Third ed.).
Wiley Publishing
. p. 291.
ISBN
978-0-7645-4986-1
Lawrence, Eric (2014-03-06).
"Browser Arcana: IP Literals in URLs"
IEInternals
Microsoft
. Retrieved
2016-04-25
Morrison, Michael Wayne
(2006). "Hour 5:
Putting Namespaces to Use
".
Sams Teach Yourself XML
Sams Publishing
. p. 91.
Whitehead, E.J (1998). "WebDAV: IEFT standard for collaborative authoring on the Web".
IEEE Internet Computing
(5):
34–
40.
doi
10.1109/4236.722228
ISSN
1941-0131
Further reading
edit
URI Planning Interest Group, W3C/IETF (2001-09-21).
"URIs, URLs, and URNs: Clarifications and Recommendations 1.0"
. Retrieved
2009-07-27
"On Linking Alternative Representations To Enable Discovery And Publishing"
World Wide Web Consortium
. 2006 [2001]
. Retrieved
2012-04-03
External links
edit
URI Schemes
IANA
-maintained registry of URI Schemes
URI schemes on the W3C wiki
Architecture of the World Wide Web, Volume One, §2: Identification
– by W3C
W3C URI Clarification
Semantic Web
Background
Databases
Hypertext
Internet
Ontologies
Semantics
Semantic networks
World Wide Web
Sub-topics
Dataspaces
Hyperdata
Linked data
Rule-based systems
Applications
Semantic analytics
Semantic computing
Semantic mapper
Semantic matching
Semantic publishing
Semantic reasoner
Semantic search
Semantic service-oriented architecture
Semantic wiki
Solid
Related topics
Collective intelligence
Description logic
Folksonomy
Geotagging
Information architecture
iXBRL
Knowledge extraction
Knowledge management
Knowledge representation and reasoning
Library 2.0
Digital library
Digital humanities
Metadata
References
Topic map
Web 2.0
Web engineering
Web Science Trust
Standards
Syntax and supporting technologies
HTTP
IRI
URI
RDF
triples
RDF/XML
JSON-LD
Turtle
TriG
Notation3
N-Triples
TriX
(no W3C standard)
RRID
SPARQL
XML
Semantic HTML
Schemas, ontologies and rules
Common Logic
OWL
RDFS
Rule Interchange Format
Semantic Web Rule Language
SHACL
Semantic annotation
COinS
GRDDL
Microdata
Microformats
RDFa
SAWSDL
Facebook Platform
Common vocabularies
BIBFRAME
BIBO
DOAP
Dublin Core
MODS
MADS
FOAF
Schema.org
SIOC
SKOS
Microformat vocabularies
hAtom
hCalendar
hCard
h-feed
hProduct
hRecipe
hReview
Uniform Resource Identifier (URI) schemes
Official
about
acct
crid
data
file
ftp
geo
gopher
http
https
info
ldap
mailto
nfs
nntp
sip / sips
tag
telnet
urn
view-source
ws / wss
xmpp
Unofficial
coffee
ed2k
gemini
feed
finger
irc / irc6 / ircs
ldaps
magnet
rsync
ymsgr
Protocol list
Hypermedia
Basics
Hypertext
Hyperlink
Hypertext fiction
Hypervideo
Adaptive hypermedia
educational
authoring
Hyperlinks in virtual worlds
Resource identifiers
Uniform resource identifier
Internationalized resource identifier
Uniform resource name
Uniform resource locator
Extensible resource identifier
Persistent uniform resource locator
Semantic URL
Concepts
anchor text
click path
Domain name
click here
Copyright aspects of hyperlinking and framing
deep linking
Fat link
URI fragment
Hostname
Hypertext
Inline linking
inbound link
backlink
HTTP referer
image map
Internal link
Internet bookmark
linkback
Link relation
Link rot
Object hyperlinking
Path
Screen hotspot
Source tracking
transclusion
URI scheme
URL normalization
URL redirection
Website
Web page
XML namespace
Technology
CURIE
Hypertext Transfer Protocol
XLink
See also
Digital poetry
History of hypertext
Interactive novel
Interactive fiction
Timeline of hypertext technology
Copyright aspects of hyperlinking and framing
World Wide Web
History
Domain Application Protocol
Authority control databases
National
United States
Israel
Other
Yale LUX
Retrieved from "
Categories
Application layer protocols
Internet protocols
Internet Standards
Semantic Web
URL
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