Among the villain items in the armory are Penguin's umbrellas and Riddler's cane.
While Crane is talking to Barbara Gordon in her cell via remote camera (in what appears to be a daily taunting) he ends his conversation by telling her to stay tuned to the same Crane Channel & same Crane Time in an homage to the 1960's Batman TV Show.
Reference is made to Keaton Avenue. Michael Keaton famously played Batman in the movies Batman (1989) and Batman Returns (1992). He's also set to be reprising his role for multiple upcoming (at the time of this episode's broadcast) projects set in the DC Extended Universe.
Mention is made of "the corner of Anton and First." Anton Furst was the production designer of 1989's Batman film.