The first usage I see of "SIP" after the title is in parenthesis after the full phrase.
Also, is this an example of irony?
Yes, the guides from American Psychological Association (APA) and Modern Language Association (MLA)
They are both the main results that appear when you google the acronyms and are quite common acronyms.
I am surprised you aren't familiar; I would expect that anyone who graduated from the US (United States of America) school system in the past 20 years would have heard of them. Are you not from the US?