What the bloody hell is wrong with you simpletons. While abbreviations can help save time, we are reaching a dangerous cliff, where the written language dissolves to nothing but letter soup.
What a waste of effort.
With that said, my personal opinion if still not clear is; you shouldnt use y for yes nor why due to the fact that it can be confusing for people to understand your intentions.
EXAMPLE
he dude have you read the news?
y
Uh
what?