Misspellings-
Misspellings are not only allowed but expected. Common is 'PH' for 'F'
and vice versa. Substitute Z's for S's.
Punctuation-
Type random emphasis characters after a post line (i.e."HeyDudes!!#$").
Slang-
Use the emphatic 'k' prefix ("k-kool", "k-rad", "k-awesome") frequently.
Capitalization-
TYPE ALL IN CAPS LOCK, SO IT LOOKS LIKE YOU'RE YELLING ALL THE TIME.
Choppy sentences-
Abbreviate compulsively ("I got lotsa warez w/ docs").