Editing Digital object identifier (section)

==Resolution==
To resolve a DOI name, it may be input to a DOI resolver, such as one at the official website <code><nowiki>https://doi.org/</nowiki></code>.

DOI name resolution is provided through the [[Handle System]], which is an infrastructure developed and operated by CNRI ([[Corporation for National Research Initiatives]]), and is freely available to any user encountering a DOI name. Resolution redirects the user from a DOI name to one or more pieces of typed data: URLs representing instances of the object, services such as e-mail, or one or more items of metadata. To the Handle System, a DOI name is a handle, and so has a set of values assigned to it and may be thought of as a record that consists of a group of fields. Each handle value must have a data type specified in its <code><type></code> field, which defines the syntax and semantics of its data. While a DOI persistently and uniquely identifies the object to which it is assigned, DOI resolution may not be persistent, due to technical and administrative issues.

Another approach, which avoids typing or [[copying and pasting]] into a resolver is to include the DOI in a document as a URL which uses the resolver as an HTTP proxy, such as <code><nowiki>https://doi.org/</nowiki></code> (preferred)<ref>{{cite web |author1=International DOI Foundation |title=Resolution |website=DOI Handbook |date=7 August 2014 |url=https://doi.org/doi_handbook/3_Resolution.html#3.7.3 |access-date=19 March 2015 |url-status=live |archive-url=https://web.archive.org/web/20150331111224/http://www.doi.org/doi_handbook/3_Resolution.html#3.7.3 |archive-date=31 March 2015}}</ref> or <code><nowiki>http://dx.doi.org/</nowiki></code>, both of which support HTTPS. For example, the DOI <code>10.1000/182</code> can be included in a reference or [[hyperlink]] as <code>https://doi.org/10.1000/182</code>. This approach allows users to click on the DOI as a normal [[hyperlink]]. Indeed, as previously mentioned, this is how Crossref recommends that DOIs always be represented (preferring HTTPS over HTTP), so that if they are cut-and-pasted into other documents, emails, etc., they will be actionable.

An interesting consequence of the fact that DOIs depend entirely on CNRI’s Handle System infrastructure (whereby CNRI operates the global root servers and wrote the protocol) is that the proxy services <code>DOI.org/<#></code> and <code>hdl.handle.net/<#></code> are interoperable. For example, the following URIs resolve to the same publication:<br>
<code><nowiki>https://doi.org/10.1016/S0021-9258(19)52451-6</nowiki></code><br>
<code><nowiki>https://hdl.handle.net/10.1016/S0021-9258(19)52451-6</nowiki></code>

There are other DOI resolvers and HTTP Proxies apart from NCRI's [[Handle System]]. At the beginning of the year 2016, a new class of alternative DOI resolvers was started by <code><nowiki>http://doai.io/</nowiki></code> (now discontinued <ref name="capsh">{{cite web |title=DOAI |publisher=CAPSH (Committee for the Accessibility of Publications in Sciences and Humanities) |url=http://doai.io/ |access-date=6 August 2016 |url-status=usurped |archive-url=https://web.archive.org/web/20160825222550/http://doai.io/ |archive-date=25 August 2016}}</ref>). This service was unusual in that it tried to find a [[paywall|non-paywalled]] (often [[self-archiving|author archived]]) version of a title and redirected the user to that instead of the [[publisher's version]].<ref>{{cite web |last=Schonfeld |first=Roger C. |title=Co-opting 'Official' Channels through Infrastructures for Openness |work=The Scholarly Kitchen |date=3 March 2016 |url=https://scholarlykitchen.sspnet.org/2016/03/03/coopting-official-channels/ |access-date=17 October 2016 |url-status=live |archive-url=https://web.archive.org/web/20161019004636/https://scholarlykitchen.sspnet.org/2016/03/03/coopting-official-channels/ |archive-date=19 October 2016}}</ref> Since then, other open-access favoring DOI resolvers have been created, notably <code><nowiki>https://oadoi.org/</nowiki></code> in October 2016<ref name="impactstory">{{cite web |last=Piwowar |first=Heather |title=Introducing oaDOI: resolve a DOI straight to OA |date=25 October 2016 |url=http://blog.impactstory.org/introducting-oadoi/ |access-date=17 March 2017 |url-status=live |archive-url=https://web.archive.org/web/20170317235707/http://blog.impactstory.org/introducting-oadoi/ |archive-date=17 March 2017}}</ref> (rebranded in 2017 as <code><nowiki>https://unpaywall.org/</nowiki></code>). While traditional DOI resolvers solely rely on the Handle System, alternative DOI resolvers first consult multiple Open Access resources such as institutional libraries with the [[Open Archives Initiative Protocol for Metadata Harvesting]] (OAI-PMH), or indexing services  based in OAI-PMH, such as [[BASE (search engine)|BASE]] (Bielefeld Academic Search Engine).<ref name="capsh"/><ref name="impactstory"/>

An alternative to HTTP proxies is to use one of a number of add-ons and plug-ins for [[Web browser|browsers]], thereby avoiding the conversion of the DOIs to URLs,<ref>{{cite web |title=DOI System Tools |url=https://www.doi.org/tools.html |access-date=7 February 2017 |url-status=live |archive-url=https://web.archive.org/web/20170208033638/https://www.doi.org/tools.html |archive-date=8 February 2017}}</ref> which depend on domain names and may be subject to change, while still allowing the DOI to be treated as a normal hyperlink. A disadvantage of this approach for publishers is that, at least at present, most users will be encountering the DOIs in a browser, [[mail reader]], or other software which does not have one of these plug-ins installed.