it's funny that 2 of the guides explain an IPO (as if we were in the dot-com boom of the late 1990s), but none spell out IOP.
I'm guessing it's related to Female Copulatory Vocalizaations,
https://en.wikipedia.org/wiki/Female..._vocalizations, but may be more.
What does IOP stand for? Interactive Oral Presentation? Imagineering Orgasms Persistently??