On February 8, AEW trademarked “Forbidden Door” and “Forbidden Portal”, according to Heel By Nature. This is seemingly related to their openness to work with other promotions such as Impact Wrestling and NJPW.
Here is the description:
International Class 025: Bandanas; Hats; Headwear; Pants; Shirts; Shorts; Socks; Sweatshirts; Undergarments; Jackets; T-shirts
International Class 041: Educational and entertainment services, namely, a continuing program about wrestling accessible by radio, television, satellite, audio; video and computer networks; Entertainment services in the nature of development, creation, production, distribution, and post-production of wrestling programs and events; Entertainment services in the nature of live wrestling performances; Entertainment services in the nature of production of wrestling programs and events; Entertainment services, namely, production and distribution of ongoing television programs in the field of wrestling; Entertainment services, namely, providing ongoing webisodes featuring wrestling via a global computer network; Entertainment services, namely, an ongoing multimedia program featuring wrestling distributed via various platforms across multiple forms of transmission media; entertainment services, namely, an ongoing series featuring wrestling provided through a global computer network.
Intent to Use: The applicant has a bona fide intention, and is entitled, to use the mark in commerce on or in connection with the identified goods/services.
The Forbidden Door phase really started by Hiroshi Tanahashi during his rivalry with Chris Jericho, which at the time was a reference to the potential working relationship between New Japan Pro-Wrestling and AEW.