IM shorthand for Monty Python fans
From ricklibrarian:
ANFSCD -- And now for something completely different
SW -- Silly walk
SES&S -- Spam, eggs, sausage & spam
RARA -- Run away! Run away!
NNNNN -- Ni! Ni! Ni! Ni! Ni!
And the one I am adopting Right Now:
NETSI -- No one expects the Spanish Inquisition! (it's funny because it's true)
...via The Shifted Librarian