The heart of hot, and the crest of cool.
1. At any given time, someone or something can be designated 'y.' No one can designate themselves 'y.' No person retains 'y' status permanently but some things can.
2. An uppercase 'Y' can be used to signal emphasis but 'y' in its common lowercase form retains the strongest value and meaning.
3. The use of adverbs should be kept to a minimum when using 'y' so as not to distract from its value and meaning. Additionally, 'y' should not be combined to phonetically complete other words and/or phrases.
4. The opposite of 'y' is 'not y.'
"You're lookin' so y right now."