In the late '90 I wrote a perl program to scan the domain database for every three letter acronym and identify the ones that were available. It came back with about five. At the time registration was $70 a year and domain squatting was a thing of the future. I determined that I could only afford one and we were coming up on "The Year Zero" so TYZ won out.
Over time it's also been Two Yellow Zebras, Three Yellow Zebras and I contemplated Tune Your Zither. Taiji Yoga Zone is a possibility and someday I will make my personal fortune with Topless Young and Zoftig. Until then, it's TYZ to you.