Template:Lighthouses completed in the YYY0s category header/doc

 is used to create categories of the form "Lighthouses completed in the YYY0s", where YYY0s is a 4-digit decade.

e.g.
 * Category:Lighthouses completed in the 1840s ✅

It is not for use on other types of categories, e.g.


 * Category:Lighthouses completed in 1784 ❌

The template creates navigation tables and puts the page into the correct parent categories

Usage
No parameters needed.