Back in the days of MSN Messenger, (Y) was a coding shortcut for the "thumbs up" emoticon. Many people continue to use this symbol to convey approval or affirmation - even in chat clients that don't support the code. This practice must be stopped. With firearms if necessary.
The thumbs-up 'emoticon' comprises the letter Y enclosed in brackets. Some people use lower case. Others plump for a capital. Either way, the end result looks something like this:
No matter how long I stare at the symbol above, I can't for the life of me make out a thumb. Is the Y meant to be the fingers? Is the 'hand' being viewed from above or side on? Or what?
To be honest, all I really see is a big 'ol butt. Or maybe a woman's low-cut blouse. (Shut up, you see it too.) One thing I definitely don't see is even the vaguest semblance of an upraised thumb.
As mentioned above, that's because the symbol isn't really supposed to resemble a thumb at all. It's just a keyboard shortcut.
The brain trust over on Quora has a pretty good explanation:
I believe this originated from the MSN days where users would use emoticons (we call them emojis now) by typing in letters/symbols and it would automatically turn into an emoticon. There was already a preset group of emoticons but users could add their own to any letter/symbol/word meaning at one point there were so many emoticons in a word you could barely read what people were saying.
(Y) was the default characters you had to type in for thumbs up, there were plenty of preset emoticons on MSN including (N) - thumbs down, :o - surprised face, :p - tongue out, (H) - cool face and many many more. Some, such as the (Y) - thumbs up emoticon had no connection to how the thumbs up looks compared to the characters you had to type in where as some, such as :o did (kind of) replicate a surprised face.
Despite no longer serving any discernible purpose, (Y) continues to thrive in the world of online chat. While nobody uses (H) or (N) anymore, the thumbs-up 'emoticon' can still be found peppered across forums and message transcripts.
Indeed, this article was inspired by an incident in my workplace's Hipchat. For several years, one of my colleagues has been dropping the (Y) multiple times a day. Half the people in the chat didn't have the foggiest idea what it was supposed to mean.
Last week, a bemused recipient finally piped up: "...Why do you keep typing butts at me?"
TLDR: stop using "old school" emoticons at work. You could end up ensnared in a sexual harassment lawsuit.