Some are again asking "why does the site use the moniker J²?"
It's really a two part story.
I am a "jr". That means that I am named "after my Dad". His name is Jerry. Thus, I am Jerry Jr. Interestingly, I have never really been called "Jerry Jr." From as early as I can remember, I have been called "J.J." — except of course, at work, where I am simply called "Jerry".
Here ends Part One — My name is "J.J."
I attended UC Davis for my law degree. I decided to not focus entirely on law while I was there. One of the "diversions" was learning how to Scuba dive. Now realize that I was at a university. Everything must fit into a semester long format. It matters not whether it is (i) "non-linear differential equations" or (ii) learning how to start a charcoal grill. One semester. No longer. No shorter.
So, this was not your one-hour resort scuba class.
And it was taught by wacko ex-NAVY seals — at least, I recall that they were ex-NAVY seals — they felt like wacko ex-NAVY seals — so I will just go with it — its not like you can ever track down someone like that and ask. These folks did the "I only have one name" thing way before Cher. Their leader was a guy named "Omaha".
For this class we had to buy a whole bunch of "stuff". They called it "snorkel gear" but I think that they got kick-backs from the local dive shop — but I digress. There was a lot of gear. On the first day, these folks asked us to take out our little bottles of white-out (yes, "white-out" was labeled snorkel gear — or more appropriately, it was for labeling our snorkel gear) and place our "mark" on each item of our gear.
"I want some small unique mark that clearly identifies the item as yours," Omaha says. "For example, J.J.'s mark should be J²".
And well that mark has stuck.