its usage is heavily preferred over full words in written communication. the desire for using encryption became a fashion thus a separate language on its own. if shakespeare would sms his friend it would have looked something like this:
2 B, or nt 2 B: dats d Q:
Whether dis nobler n d mind 2 suffA
d slings n arrows of outrageous fortuN,
Or 2 taK arms agenst a sea of trblz,
n by opposing Nd em? 2 di: 2 zzz
he wrote this instead:
To be, or not to be: that is the question:
Whether 'tis nobler in the mind to suffer
The slings and arrows of outrageous fortune,
Or to take arms against a sea of troubles,
And by opposing end them? To die: to sleep;