Category:CS1 maint: Extra text

It is used to build and maintain lists of pages—primarily for the sake of the lists themselves. They are not part of the encyclopedia's 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 citation parameters that have parameters that contain text that duplicates static text provided by the template. For example, |edition=2nd ed will be rendered as (2nd ed ed.). Pages in this category should only be added by Module:Citation/CS1.

While most of the Citation Style 1 and Citation Style 2 error messages are visible to all readers, some remain hidden. Editors who wish to see all of the CS1|2 error messages can do so by updating their common or skin CSS stylesheet to include:

.citation-comment {display: inline !important;} /* show all Citation Style 1 error messages */

Even with this css installed, older pages in Wikipedia‍ 's cache may not have been updated to show these error messages even though the page is listed in one of the tracking categories. A WP:NULLEDIT will resolve that issue.

The above code is required if you wish see maintenance category messages:

Category:CS1 maintenance (link)