4K (computer virus)
4k is a computer virus which infects COM files and EXE files. The virus was one of the first to employ stealth tactics. Infected systems will hang, after September 22 every year, which is also the date of birth Bilbo Baggins, a character from "The Lord of the Rings". The code was intended to display the message "Frodo Lives", but hangs in all known variants.
4K resolution
The CEA definition does allow manufacturers to use other terms—such as "4K"—alongside the Ultra HD logo. Since the resolution in CEA's definition is only a minimum requirement, displays with higher resolutions such as 40962160 or 51202880 also qualify as "Ultra HD" displays, provided they meet the other requirements.