Template:Decade in US state category/doc

Purpose
This template is intended to be used on decade in US state categories (for example, Category:1930s in Oregon or Category:1970s in Wyoming). It creates a "timeline" style table of links to categories for adjacent years before or after it in the same decade.

Syntax
No parameters are needed, and none are available

Error-checking
The template checks that the page:
 * 1) is a category
 * 2) has a title of the form "YYY0s in Foo"

If either of those conditions is not met, an error message is displayed and no other output is generated, but the page is added to a tracking category:
 * Category:Errors reported by other category header templates (population: )

Note that this category is also used by many other category header templates