Sarcasm is very hard to get across when using the internet, so typing SARC-INT will make sure people get your hint from the get-go, and saves you precious time explaining that you were actually being sarcastic
Without SARC-INT:
Person 1 - "I love that hat ur wearing in ur prof pic."
Person 2 - "Really?"
Person 1 - "I was being Sarcastic."
Person 2 - "Ahh right, yeah lol I was forced to wear it."
With SARC-INT
Person 1 - "I love that hat ur wearing in ur prof pic. (SARC-INT)
Person 2 - "Yeah tell me about it lol."
It is a very evil little place that controls all spaces and calendars pertaining to student org activities, run by tiny little gremlins 'interns' and one big gremlin 'mike' armed with computers and the singular ability to order white folding chairs. they are here to 'help' you. ostensibly.