Well, in Julia it's an incomplete expression (Y is a variable, % is the infix operator for remainder, and # a line comment (the $ is used for string/command interpolation, but is commented out).
Given that some of the characters in the original were italicised, I think that there were probably some stars in there that Markdown ate. My question wasn't really what operation it performs or tries to perform, but rather what abakus (https://news.ycombinator.com/item?id=17473616) meant by comparison with lower_UPPER_CamelCase.