leet 
(lēt)
(lēt)n.
A variety of spelling that uses numbers and symbols that approximate the shape of certain letters, using for example 1 and 5 for i and s, used primarily in texting and other typed electronic communication.
[From l33t, alteration and leet respelling (using 3 for E) of elite (in reference to the use of such spellings by those with elite, or privileged, access status on early computer bulletin boards ).]