General fact: 204 is the HTTP status code indicating the request was received but there is no response to the request.
Mathematical fact: 204 is a member of the Mian–Chowla sequence, being the smallest number after 182 such that the pairwise sums of the previous terms are all distinct.
Trivia: 204 is the HTTP status code indicating the request was received but there is no response to the request.
Historical date: July 22nd is the day in 1997 that the second Blue Water Bridge opens between Port Huron, Michigan and Sarnia, Ontario.