Step into an elevator in a Korean hospital or apartment block and the fourth-floor button may say F, and there is a reason. The Sino-Korean word for four sounds exactly like the word for death, so the number gets quietly avoided in floor and room numbers

Korean cultural resources describe exactly this: in many South Korean hospitals the fourth floor is omitted, or the letter F stands in for the fourth floor instead. Where the F actually shows upThe substitution is most visible in tall buildings, but it doesn’t stop at the elevator panel. In many South Korean buildings, the fourth floor is either labelled F or skipped altogether, and the habit extends inward to room numbering. Korea.net notes that while fourth floors may sometimes appear in ordinary buildings, they are generally not found in Korean hospitals. Awhy the fourth floor says F and you’ll get a clear, almost cheerful answer about a homophone.