Mark isn't the only Bachelor codename we've heard, however.
Whilst Matt Agnew had his winner Chelsie McLeod as 'Rose' in his phone, last year's stars Locky Gilbert and Irena Srbinovska's nicknames for each other were Roger Roger and Doug, respectively.
"Douglas is Locky’s middle name so that’s where I got it from and no one picked up on that!" Irena explained to WHO after their season.
Locky added: "I have no idea where Roger came from, I just thought it was funny!"
Since their time on the show, Jimmy and Holly have moved in with each other in Sydney's Bondi.
Last week, Jimmy shared a photo of himself and his new leading lady holding a wrapped gift and card addressed to them along with a bottle of Dom Perignon champagne.
"All smiles to have settled on the new digs. Guess who my roommate is?" he captioned the post.
The best comment came from Carlie Hodges, who came in fourth place and was close with Holly throughout the Bachelor experience.
"Yayyyy! Hol told me the spare room is actually being named ‘Carlie’s room’ - good choice 👌🏻🥳," she joked.
Though Sydney is still in the midst of lockdown, Jimmy and Holly revealed they just want to appreciate the little things now they're off the show.
"So, we're really looking forward to getting back to normal life. Introducing each other to our friends and having family dinners and stuff like that when we can."