Many of Quality's character and title trademarks were sold to National Comics Publications (now DC Comics), which chose to keep only four series running: "Blackhawk", "G.I. Combat", "Heart Throbs" (each for another 100 or more issues) and "Robin Hood Tales" (for 8 issues). There has been much confusion over whether the original Quality Comics and/or the characters they published are in public domain. The original copyrights for Quality's publications have never been renewed by either Arnold or DC (as no such renewal is on file with the Library of Congress), leaving those original stories in the public domain. However, the trademarks to the characters, and to the titles of the various comic book series, were sold to DC, which has periodically published stories with them in order to keep their claims alive.