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1.
Rolling Up Stairs Laughing

Similar to ROFL (Rolling on floor laughing), RUSL is used to respond to the next level of humour.
RUSL should only be used for special occasions when something is amazingly funny, otherwise its strength and impact will be lessened considerably.

"<insert mindblowingly funny statement here, too funny to be reproduced for a definition here>"
"RUSL!"
by Chris' Sister November 04, 2007