Help:CS1 errors

Help:CS1 errors is a help page on Wikipedia that explains the error messages produced by CS1 citation templates. CS1 stands for "Citation Style 1", a system of templates used to format article references in a consistent manner, such as {{cite web}}, {{cite book}}, {{cite news}}, and {{cite journal}}.

When an editor fills in a parameter incorrectly or omits a required one, the Lua code underlying the template generates a short red error message beneath the reference. The message typically contains a link to the relevant section of the help page, so that the editor can understand the problem and how to fix it.

How it works

CS1 templates are based on a Lua module (usually named Module:Citation/CS1). The module validates parameter names, values, and format. If an error is found, it produces an error message and adds the page to a specific tracking category to monitor articles needing correction. Some messages are visible to all readers, while others (small icons) appear only to editors using specific CSS settings.

Common types of errors

These include unrecognized parameters (incorrectly named), invalid URLs that do not match the expected format, dates that do not conform to accepted patterns, missing titles when required, and identification numbers such as ISBN or DOI that fail length or checksum validation. There are also messages relating to conflicting use of parameters that should not be mixed, for example when a URL is provided but a title is omitted.

How to fix errors

The standard approach is to view the page source, locate the reference indicated by the error message, and compare its parameters against the official list for that template. Correction usually involves fixing a parameter name, supplying a missing value, or removing an unnecessary parameter. If the information being cited cannot be found, it may be possible to switch to a different, more suitable template.