Templates

I’ve been reading through the docs and FAQ and there stuff on templates but I can’t find the answer to this simple question. I’ve duplicated one of the templates and made a small change to it, let’\s call int template-edit.php.

When I go to “Manage > Pages > About > Edit > Page Template” template-edit.php does not appear as one of the options. How do I make it appear there?

I know it’s in the docs somewhere, damned if I can find it.