Oh, please do not use short forms all the time.
There was once when my friend used the word "testi" as the short form of "testimonial" (quite a common practice among Friendster users, I think). That was okay if used in singular form.
However, I saw her using this short form for the word's plural form, too. What do you get?
"Testis".
So please, for your good and mine, do not use short forms inappropriately!