The reason this is a complete scar on all of mankind is that it's an acronym that include an abbreviation.
Remember kids, 'You' is spelled with a 'Y', not a 'U'.
When forming acronyms, please keep in mind that, they are meant for shortening speech/text. If someone has to ask you what it means, you have thus failed. It then will require more effort to explain you were trying to be fancy.
Samantha: wtf does ttul mean?
George: don't worry about it i gtg.
Samantha: wait, what does it mean, i have to know...
George: *sigh*, omg, okay, it means talk to u later.
Samantha: Oh, i thought that was ttyl.
George: Yeah, but i'm cooler than that.
*Samantha has signed off*