This morning my students informed me that a period in a text message indicates anger. "Like your friend texts you about something and you just write back one word with a period," they said. "You sound pissed."
How about one word without the period? Not angry, just in a hurry.
Also, "OK" sounds like you're angry but "okay" does not. Worst of all is "K." "K." is the equivalent of "Yeah, yeah, I'm busy. Stop bothering me."
I want a list of these rules. Not because I want to use them when texting (all my texting is done with people like me -- so old we text in complete sentences, properly punctuated, with caps) but because it's like watching a new language being born.