During the gala, the gang uses code names based on the names of actors who have played Batman: Michael Keaton, Christian Bale, Adam West, Val Kilmer, George Clooney and Voice of Diedrich Bader. The code they use to talk to the group at large is "Belfry", which is based on the phrase "bat in a belfry", meaning insanity. Britta is given the Batman themed codename of "Clooney" after the actor George Clooney who starred in Batman & Robin (1997). The film is generally considered to be the worst in the Batman franchise.
The scene with Dean Pelton in the elevator is an homage to the elevator scene with Captain America in Capitán América y el soldado del invierno (2014). That movie was written and directed by the Russo brothers, who also wrote and directed many episodes of "Community".
The following phrases are written on the whiteboard: A Crafted Narcs, Scare and Raft, Aced Narc Frat. These are all anagrams of Frankie's name, Francesca Dart.
Custodian Lapari, played by Kumail Nanjiani, calls Abed "the Indian guy". When Abed replies "I'm Arabic", he says "Gah. Okay, let's go with that." This is a reference to the fact that Danny Pudi is not Arabic, he's half Indian and half Polish. Iqbal Theba, who plays Abed's father, is also not Arabic, he's Pakistani.
Frankie uses a popular quote from Joseph Campbell: "Follow your bliss". Dan Harmon has often spoken of Campbell's influence on his writing.