An extension to field_formatter_settings that allows you to set a field that contains multiple values to display in reverse order.
Use-case for this was a 'publication' that had many 'issues' that were attached via entityreference.
It was easy to add new items at the bottom, but when displaying a 'teaser' for that publication, it made sense to display just a few 'issues', and the most recent first.
A similar case could be when adding images to a content type to use as a slideshow. Maybe in the teaser you want to show the most recently added image or attached file.
This could also be done via an embedded view, or by requiring the editor to always drag their items to the top ... but this should be a trivial display option to live alongside the other filed_formatter_settings like field_multiple_limit