Ⓚ, the "all rights reversed" symbol used by the Principia Discordia.[1][2] Uploaded to Wikimedia Commons in 2006 as a symbol for the dwarf planet Eris, and since 2012 used for Eris on a website at the w:Sternberg Astronomical Institute that appears to have copied from Wikipedia.[3] Perhaps intended as a simplification of ⟨⟩, as a spelled-out ⟨⟩ had been suggested as a symbol for the dwarf planet Eris on the Discordian discussion board[4] that settled on ⟨⟩, which is now in Unicode.
Own work
User:Eris