Auto-suggest item format field

One of our users is wondering if the format field in the Edit Item interface (e.g. /admin/items/edit/...) should auto-suggest or offer dropdown options to select a MIME type. It is her recollection that this should be the case; however, our Omeka instance doesn't have such a functionality. Is she imagining this feature? or does it exist and we just need to configure it to get it to work?

If you install the Simple Vocab plugin, you can create lists which will populate a dropdown.

thanks! I'll give it a try.