All single-sided non-token/advertising Magic: the Gathering cards, to date, should have a back that looks like one of the above images. Note that double-faced cards will obviously not have a standard Magic back.
This identifier system is based on the document produced by Mainstream Design (2001), and updated by 108Bits (2018), and Vince (2019). It has been updated by The Relentless Dragon, in 2021. All symbols, images, and set/card names are the property of Wizards of the Coast, a division of Hasbro, Inc., and used under educational fair use.