Help:Cite errors/Cite error ref too many keys

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

Any footnote can be assigned to a group:
 * content

Or both:
 * content

Issues and resolutions
A named reference tag can't have too many names or parameters.

Forgetting quotation marks around a name containing one or more spaces
A quoteless, multiple-word name such as   will be parsed as two separate names due to the space, thus generating the error.

Also, you can only specify two parameters:  and. You can't, for instance, format a reference with content, or give it an id.

A good, quick solution that is likely to work is to add double quotes around the entire name. For example, replace:

with:

Forgetting
Forgetting  can also cause this error.

Although  is mentioned throughout this help page, when troubleshooting this error, it's easy to focus on searching for problems with the name while forgetting to make sure   is there. This is especially true when editing on the mobile version of Wikipedia, since the editing tools are scaled down to improve performance, so you can't just click on the correct code under the edit window.

Remember, to use any troubleshooting help page successfully, double-check any error-causing wikitext against every single piece of the example code.

Attempting to create a note
You might be trying to create a reference in the "note" group. That is, a reference displayed in the Notes section instead of the regular References section.

In other words, you might be here because you attempted something like  to achieve. Doing so leads to the error message discussed here.

The solution is to instead use the efn template:.

Examples
In this example, reference 1 is named, which is invalid due to the space. In reference 2  is valid as it is enclosed in quotes and reference 3 is valid as   uses an underscore.

{{pre| Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. 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. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Curabitur pretium tincidunt lacus. Nulla gravida orci a odio. Nullam varius, turpis et commodo pharetra, est eros bibendum elit, nec luctus magna felis sollicitudin mauris. Integer in mauris eu nibh euismod gravida.

Bugs

 * (comment #Cite error ref too many keys not generated if name chunk contains other than A–Z, a–z, 0–9)

This error is not generated if the name fragment after the space contains (not just begins) any other character than A–Z, a–z, 0–9. When this condition occurs, the link is truncated after the space. In this example, although the name fragment after the space contains a different character, all three references generate the same link:

{{pre| Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. 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. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Curabitur pretium tincidunt lacus. Nulla gravida orci a odio. Nullam varius, turpis et commodo pharetra, est eros bibendum elit, nec luctus magna felis sollicitudin mauris. Integer in mauris eu nibh euismod gravida.