Template:Shelf:Ancestry/doc

Usage
Use this template on the ancestry page of a shelf in the ; anything on the ancestry page other than the template call should be d.

The name of the ancestry page is formed by appending suffix "/ancestry" to the name of the shelf page, thus.

One parameter is required:
 * &mdash; a wikilisp-formatted list of all ancestors of the shelf.

The ancestor relation is the closure of the parent relation supported by the shelf pages (see Shelf:Page). As with parents, ancestors may be shelves or departments.

When called with non-blank first unnamed parameter (with value other than ), or when viewed from a non-ancestry page, this template provides its ancestors list, or, if the first unnamed parameter has value   is non-blank, the template returns the pagename of the template itself,. If viewed from an ancestry page (without overriding parameter), this template checks for problems with the associated shelf page and, if found, displays a notice explaining the problem and suggesting how to fix it, with buttons to perform likely remedial actions.

Internals
This template itself determines which sort of information request is being made, and either provides information directly, or delegates the display function to /display.