Editing the Innovation Theme Core Files

[Carlos]

Even when the wiki says:

As of 3.1, you can force the page editor's “Template” dropdown to ignore partial template files by naming them with a .inc.php extension. For example, a user will not be able to choose footer.inc.php as a page template because it's file extension will prohibit it from ever showing in the select box.

this is not correct. All files with the extension .php are listed ;=)

That information in the wiki is (was) correct, because it's not related to the theme editor, but to the page editor.