Category:CS1 errors: empty unknown parameters

It is used to build and maintain lists of pages—primarily for the sake of the lists themselves. They are not part of the knowledge base categorization scheme.

More information:

This category is hidden on its member pages—unless the corresponding user preference is set.
These categories are used to track, build and organize lists of pages needing "attention en masse" (for example, pages using deprecated syntax), or that may need to be edited at someone's earliest convenience.
These categories also serve to aggregate members of several lists or sub-categories into a larger, more efficient list (discriminated by classifications).

Administrators: Please do not delete this category even if it is empty!
This category may be empty occasionally or even most of the time.

This is a tracking category for CS1 citations that have empty parameter whose names are not known.

Help desk

Cite has empty unknown parameter: |<param>=
Cite has empty unknown parameters: |<param1>=, |<param2>=, ...

This error message is hidden. To show this error message see Controlling error message display.

This error message highlights CS1|2 templates that hold empty parameters with names that are not known to CS1|2. This error message is a companion to Unknown parameter |xxxx= ignored.

Empty positional parameters, which typically look like two adjacent pipes in a template, | |, or a pipe and then the end of the template, |}}, are identified as numbered parameters: Template:Error-small. Similarly, a pipe followed by an HTML comment that encloses everything before the next pipe or closing brace, |  | will be identified as an empty numbered parameter. Parameters that have both a pipe and an equal sign but do not have a name are identified as empty-string parameters: |= or | = → Template:Error-small. Various templates that wrap CS1|2 templates may cause this error when they use constructs like this: |{{#if:{{{2|}}}|title}}={{{2|}}}. When {{{2|}}} does not have a value, the template creates |=.

To resolve this error, remove the extra pipe, correct the parameter name, or remove the parameter from the CS1|2 template.

Pages with this error are automatically placed in Category:CS1 errors: empty unknown parameters.^[a]

Notes

^ Pages in the Book talk, Category talk, Draft talk, File talk, Help talk, MediaWiki talk, Module talk, Portal talk, Talk, Template talk, User, User talk, and Wikipedia talk namespaces are not included in the tracking categories. In addition, pages with names matching the patterns '/[Ss]andbox', '/[Tt]estcases', '/[^/]*[Ll]og', and '/[Aa]rchive' are not included in the tracking categories.

This category currently contains no pages or media.

[categories-1] Pages in the Book talk, Category talk, Draft talk, File talk, Help talk, MediaWiki talk, Module talk, Portal talk, Talk, Template talk, User, User talk, and Wikipedia talk namespaces are not included in the tracking categories. In addition, pages with names matching the patterns '/[Ss]andbox', '/[Tt]estcases', '/[^/]*[Ll]og', and '/[Aa]rchive' are not included in the tracking categories.

[a]