One of the more personal things they share in the first few episodes is their private (and now, not so private) nicknames for each other.
Meghan calls Harry "Haz," as do others in his social circle, per the documentary — it's a common nickname for Harry in the U.K. In fact, Harry is already is a nickname: The royal's official birth name is Henry Charles Albert David.
The couple also refers to each other as "H" and "M" (not to be confused with the Swedish fashion retailer H&M) throughout the documentary.
Online, Meghan and Harry's first initial nicknames have proven to be as divisive as other aspects of the documentary, like the Duchess of Sussex recreating her initial idea of a curtsy.
Yes, we know what you're thinking: Who cares about anyone's nicknames that much? Apparently, a lot of people — especially when it comes to the duke and duchess.
Some, it should be said, find the nicknames endearing, with one Twitter user writing that she "melts" at the fact that Harry calls Meghan "M."
Others are less enthused. As one viewer of the series tweeted, "The Meghan and Harry doc is great but can’t we all agree that calling him H as a nickname is ridiculous."
"I know nicknames are personal, but Meghan and her pals calling Harry ‘H’ sends cringe trickles throughout my viens (sic)," another tweeted.
For some, this was a turning point in how they saw the couple, who stepped back from their roles as senior royals in 2020 and moved to North America. One Twitter user joked that, while she'd always thought Harry and Meghan seemed "fine and cute," finding out they call each other "M" and "H" was "irredeemable."
"Harry and Meghan calling themselves H and M got to be the biggest ick I’ve ever seen," another wrote.
Clearly, people have some strong thoughts about those one-letter nicknames. The blowback got us thinking, though: Harry and Meghan can't be the only couple on earth to call each other by their shortest names.
To get to the bottom of the internet's latest "ick," TODAY spoke to other folks who pull a Harry and Meghan, and found out how their first initial nicknames came to be.
Gabrielle Spann, who lives in San Francisco with her boyfriend, says she calls her boyfriend "J" for "Joey," but it wasn't her idea. Rather, the nickname is a bit of a family tradition.
"It's actually something I picked up from my grandmother and mom. My dad and brother both have names that start with the letter J, and they'd always say it. When I started dating Joey, I'd find myself randomly saying it as well," she tells TODAY.com.
TODAY also spoke to Sabrina Caruso, who calls her girlfriend Bea "B" — which, coincidentally, is Sabrina's childhood nickname too.
Another person, who chose to stay anonymous for this piece, revealed to TODAY that he and his ex-girlfriend used to call each other their initials for a nickname too. They got the idea from the hit 2000s show "Gossip Girl."
"I honestly think it had to do with her obsession with 'Gossip Girl' a little bit," he tells TODAY.com. "However, it was our own cute little way of communicating with each other. We didn't necessarily like pet names, but we wanted something that was ours."
Pet names are a way to demonstrate affection, according to experts. Gia Tims, who lives in Nashville, felt that initials were the only route to a nickname for her partner Kaden.
"When I met him, I realized he couldn't really make a nickname out of that. I love giving people nicknames, especially people I like. His last name starts with a P, so I instantly asked him if anyone ever called him KP. Now it's just a sweet thing between the two of us that we think is fun," Tims says.
So, even though "Haz" and "Meg" may have some nickname haters on their heels, they're certainly not the only ones utilizing them.