For everyone that likes Warhammer 40k Tabletop and Dawn of War Games or anything to do with Warhammer 40K.
The Adeptus Custodes have noticed a large cup shape cut out on the Emperor's suit of power armor. When confronting the Blood Ravens as to why, they simply state it was a gift from the Emperor himself for defending Terra during the Horus Heresy. Official documents have never been found.
The description was a lol.