Help:Cite errors/Cite error ref no key

This page will help you to fix the cite error message:

• If you have read this help page and find something missing or confusing, please discuss it at the main talk page.
• Please reference this page and the page where you have the problem so we can understand your issues.
• For basic information on the footnotes system, see Referencing for beginners; for advanced help, see Footnotes.

Overview

Further information: WP:REFNAME

A footnote used multiple times may be defined with a name:

<ref name="foo">content</ref>

To invoke a named footnote:

<ref name="foo" />

Issues and resolution

A named reference has a malformed name. This is produced by a construct like <ref /> or by an invalid footnote name; either create a full reference such as <ref>content</ref> or give the tag a name like <ref name="refname" />.

Names

Names for footnotes and groups must follow these rules:

• Names are case-sensitive. Please do not use raNdOM capitalization.
• Names must not be purely numeric; the software will accept something like ":31337" (which is punctuation plus a number), but it will ignore "31337" (purely numeric).
• Names should have semantic value, so that they can be more easily distinguished from each other by human editors who are looking at the wikitext. This means that ref names like "Nguyen 2010" are preferred to names like ":31337".
• Names must be unique. You may not use the same name to define different groups or footnotes. Try to avoid picking a name that someone else is likely to choose for a new citation, such as ":0" or "NYT".
• Please consider keeping reference names short, simple, and restricted to the standard English alphabet and numerals. If spaces are used, the following technical restrictions become relevant:
  • Quotation marks are preferred but optional if the only characters used are letters A–Z, a–z, digits 0–9, and the symbols !$%&()*,-.:;<@[]^_`{|}~. That is, all printable ASCII characters except #"'/=<>?\ and space.
  • Inclusion of any other characters, including spaces, requires that the reference name be enclosed in quotes; for example, name="John Smith". But quote-enclosed reference names may not include a less-than sign (<) or a double straight quote symbol ("), which may however be included by escaping as < and " respectively.
  • The quote marks must be the standard, straight, double quotation marks ("); curly or other quotes will be parsed as part of the reference name.
• You may optionally provide reference names even when the reference name is not required. This makes later re-use of the sourced reference easier.

Examples

In this example, reference 1 improperly starts with <ref />:

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.<ref/>Reference 1</ref> Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.<ref>Reference 2</ref> Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.

==References==
{{reflist}}

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.Reference 1</ref> Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.

Technical

Pages with this error message are placed into Pages with incorrect ref formatting. The system message page is at Cite error ref no key.