Wikipedia:Tip of the day/August 19, 2006
Subpages are pages that are separated with a "/" from their parent page, for example, User:Eloquence/Favorite Wikipedia quotes. When you visit a subpage you will see a backlink (aka breadcrumb) near the top of the page back to the parent page. Subpages are allowed only in the User:, Talk: and Wikipedia: namespaces. They are not enabled in the article namespace, because many articles might qualify as subpages of more than one page. Instead, follow article naming conventions and include links to related subjects in the text. Subpages can be useful for organizing and archiving content. You can create a subpage by typing [[/Name]] on the page in question. If you end the link with a slash, e.g., [[/Name/]], the slashes are hidden in the output.