Category:Sidebars with styles needing conversion is a maintenance category to identify templates and modules using a sidebar with an argument with the word 'style' in it (or the 'width' parameter). The specific parameters are listed at Template:Sidebar#Deprecated parameters. This category will only appear on templates and modules which do not have the words "testcase", "sandbox", and "doc" in their titles.

This is a maintenance category, used for maintenance of the Wikipedia project. It is not part of the encyclopedia and contains non-article pages, or groups articles by status rather than subject. Do not include this category in content categories.

This category is not shown on its member pages unless the appropriate user preference (appearance → show hidden categories) is set.

This category has a backlog that requires the attention of willing editors. This notice will hide itself when this category has fewer than 100 items. (recount)

These templates should be fixed to use TemplateStyles (sidebar documentation) using |templatestyles=, |child templatestyles=, and |grandchild templatestyles= where appropriate. See sidebar documentation for some quick rules of thumb.

A specific real conversion example is Template:DYK tools where the styles were moved to Template:DYK tools/styles.css.

An example of two kinds of template that will trigger this category is:

{{Sidebar
| title = Title
| style = width: 18em;
}}

{{Sidebar
| title        = Title
| headingstyle = background: green;
| heading1     = Header1
| content1     = Content1
}}