Fox Features Syndicate was an American comic book publishing firm established by founder Victor A. Fox in the 1930s. Fox was originally an accountant for DC's predecessor, National Periodical Publications, who saw how lucrative they had been and decided to start up his own publishing house along with partner Bob Farrell. Fox generated two notable properties that eventually became part of the greater DC Universe stable of characters: Blue Beetle and Phantom Lady.
Artist Charles Nicholas was provincial in the development of the original Golden Age Blue Beetle, who would enjoy moderate success over the decades, albeit with an irregular publishing history. The Blue Beetle would also undergo a major overhaul when Charlton Comics acquired the rights to the character in 1964.
Phantom Lady was another story. She was originally created by Will Eisner for Quality Comics' Police Comics #1. Her run of adventures had ended years before, so in 1947, Jerry Iger's Iger Studios, believing that he could do that, assigned the stories to Fox. Fox published new material on her; when he went under, the character passed to Ajax-Farrell. However, DC Comics had bought the Quality stock of characters in 1956, and believed these included Phantom Lady. They did not register the name as a trademark, nor did they use her until 1973, after she had already fallen into the Public Domain. Because of her status in legal limbo, several publishers, including IW and Charlton, published reprints of Fox or Quality stories in the 60s and 70s. As DC only owns the Quality character, the Fox, Ajax-Farrell and AC Comics adventures are not theirs.