Who’d have thought that Apple had such huge Harry Potter fans:
The SMC, or system management controller, is a chip used to regulate a Mac’s current and voltage, manage its light sensor, and temporarily store FileVault keys. Turns out that the SMC contains undocumented code that is invoked by entering the word “SpecialisRevelio,” the same magic words used to reveal hidden charms, hexes, or properties used by wizards in the Harry Potter series written by author J. K. Rowling.
via “SpecialisRevelio!” Macs use Harry Potter spell to unlock secret “backdoor” | Ars Technica.