A while back I posted about the semiotic use of the number "3" for the letter "E" in the title of an album by T-Pain. There is actually an orthographic computer language called Leetspeak that uses numbers and characters to replace as many letters as possible in a computer communication.
S3mi07i(5 i5 7-3 br4\(- 0f 1i\gui57i(5 7-47 i5 (0\(3r\3d wi7- 7-3 r3147i0\5-ip b37w33\ 4 5ig\, w-47 7-3 5ig\ r3pr353\75 4\d -0w p30p13 i\73rpr37 7-3 m34\i\g 0f 7-3 5ig\.
Leetspeak was named after the "elite" status classification used on bulletin board systems in the 1980's. The unusual orthography was originally used to encrypt communications but it also became a way to indicate a person was knowledgeable about computers and the culture of computer users.