In the mid-60s and early 70s, DC Comics sent out a form letter to Superman Family fans who often wrote in with variations of the same questions about Superman and related characters. The information was provided on greenish-gray paper which was folded into an envelope and mailed out.
   There were two known versions of the FAQ letter. They can be timestamped by the names of the members given for the Legion of Super-Heroes and Substitute Heroes. In the first letter, Star Boy and Dream Girl are included in the Subs line-up, so the issue date for this would have been sometime in 1966, before ADVENTURE COMICS 350 came out (when Nura and Thom rejoined the Legion).
   The second version includes members such as Karate Kid, Shadow Lass and Chemical King, so would have been issued around late 1968. There is slightly more content overall, and the 'Publishers' signature at the end of the letter was also stylized. By this time, DC Comics had moved offices from Lexington Avenue to Third Avenue, NY.


The first version of the letter. Click on image for a bigger view.

The second version. Click on the image for bigger view.


A close-up of the Legion membership information from the original letter.


A close-up of the Legion-related excerpts from the updated version.