Template:Shelf:Check category/doc

This template checks the status of an expected shelf category page.

Usage
Place this template on a page that expects the shelf category to exist. The only parameter expected, as of this writing, is
 * &mdash; the name of the shelf, without the  prefix.

Internals
Only checks that the associated shelf category exists. If it doesn't (and if we aren't actually previewing the associated shelf category now), adds the current page to /Attention needed, generates a text message, and provides a button to create it via ordinary editing of a wikipage, requiring manually saving a preloaded template. A contemplated upgrade would detect availability of dialog and replace the editing button with one for a dialog-based assistant.