The Netflix production, "Daredevil", may be slipping an Easter Egg into a Season 3 scene as pointed out by a Tweet last Thursday. This appears to be a page in the tabloid, New York Bulletin, mentioning The Punisher. However, take a look at the blurb in the lower left hand section of that page.
The Internet is now ablaze with news stories and fan theories that this may be a reference to K'un L'un, one of Seven Capital Cities of Heaven, and the mystical city where Danny Rand learned his martial arts skills and obtained the Iron Fist powers. Nerd Fact: The Amulets Of Power all originate from the K'un L'un dimension.
The Hand also plays a role in the "Daredevil" series so that could be another possible connection. Since Season 3 of "Daredevil" won't be available until after "The Defenders" comes out it might be 2018 before we will have answers. However, "Iron Fist" premiers March 17 so expect Netflix to start laying the groundwork in that show.