Creates a category of the form "YYY0s by continent", where YYY0s is a 4-digit decade.

e.g.

{{Decade by continent category header}}

No parameters needed

If this template is used on an invalid page, then an error message is displayed, and the page is categorised in a tracking category:

Purge page to update totals

Errors include:

  • The page is not in the category namespace
  • The page's title does not take the form "YYY0s by continent"