In The Flash S04E17 Null and Annoyed, there is a conversation between Ralph and Barry as such:
An improv group made up of superheroes? We can take it to Washington.
- We'd be the DC Comics.
- No, Ralph.
Usually the Arrowverse shows reference Marvel comics and it could be taken as the comic medium that the DC universe people reads... However, how does the "DC" universe have DC comics? Is this an oversight from the showrunners or are they referencing another DC comics that I do not know about?