Origin: Acronym/Internet Slang – CSB stands for “Cool Story Bro”
CSB is usually used in online forums often as a a reply to someone who had started a thread telling a tall tale or a cock and bull story.
Forum Poster A: “Today I managed to play Pokemon Go on foot from the East to West of Singapore…a total of 40KM walked in under 4 hours!! Here are my catches for the day!! (*shows pic)
Forum Poster B: “CSB….it rained heavily the whole day across Singapore. Unless you were travelling in a car or you used GPS spoofing, you definitely did not do it on foot…”