Kl is an abbreviation for the word Cool. An example could be this.
Bob: Hey Dave, i completed the task!
Dave: Kl.
it just means cool
Inbd mean "It's no big deal" in text language.
BTW means By The Way in text language
in text language ttfn means ta ta for now
Inbd mean "It's no big deal" in text language.
defo
RUS in text means "are you serious".
gnu
who you speaking to
To Be Fair
Thinking of you
what about that or what bout that