Back in 1975, DC introduced the comic book Batman Family.
It started out as a "Giant" comic book with a new story or two and a few reprinted stories, sometimes spotlighting different past villains with a "Villain of the Issue" feature.
from Batman Family #5 (May-June 1976)
But starting With issue #11, they changed to a format with all-new material when it came to the stories. But it was also that issue that introduced the "Bureau of Missing Villains" feature.
From Batman Family #11 (May-June 1977):