This is a tracking category for CS1 citations with unrecognized parameter names.

Help desk

Citation Style 1 and Citation Style 2 templates report this error when the name portion of a parameter's |name=value pair is not recognized as a valid name. Typically, this is caused by spelling or capitalization errors or when a page is reverted to a version where the citation template did support the parameter. It can also be caused by the use of parameters that are valid in some, but not all, CS1|2 templates. For example, {{cite book}} citations are sometimes erroneously created using |title= and |work= when they should use |chapter= and |title= instead.

The CS1|2 engine does not ignore unrecognized parameters. The purpose of the citation is to properly identify the source, not to act as a repository of notes and ancillary information.

CS1|2 template parameters are lower case. CS1|2 will report this error when the parameter's name contains uppercase letters (Xxxx, xxXx, XXXX) but the parameter's name is defined as lowercase (xxxx). Some identifier parameters, like |isbn=, |pmc=, |doi=, etc., can be either lower case or upper case, but not of mixed case (|isbn= or |ISBN= but not |Isbn=). For common parameter misspellings, like |pubisher= instead of |publisher= and some former template parameters, CS1|2 will suggest a valid parameter name. The list of deprecated and recently removed parameters may contain additional information as well.

Reported unknown parameters following a |DUPLICATE_<param>= scheme are created by Citation Bot when it finds duplicate parameters |<param>= in a template.

To resolve this error, replace the erroneous parameter name with a correct one, possibly using the suggested name. Ensure that the parameter's name is correctly spelled and that there are no characters except spaces between the parameter's name and the leading vertical bar (|) or trailing equals sign (=). A list of valid parameters can be found by consulting Help:Citation Style 1 or visiting the description page of the specific template being used, such as {{cite web}}, {{cite book}}, {{cite journal}}, etc. Consider moving information associated with the unknown parameter into an appropriate parameter or to a section of the article's talk page for preservation.

Pages with this error are automatically placed in Category:CS1 errors: unsupported parameter.^[a]