Doctor Who logo (in-universe)

The logo as seen on the cover of Doctor Who Discovers Historical Mysteries. (AUDIO: The Kingmaker)

You may be looking for the Doctor Who logo from the real world.

The Fifth Doctor recalled that his book series was to be named with a comma, The Doctor, Who Discovers but became Doctor Who Discovers after "some idiot" in the publisher's design department missed the "The", creating a logo that said Doctor Who. (AUDIO: The Kingmaker)

In the mid-2000s, a new logo featured on billboard advertisements for the Doctor Who Exhibition' which were placed around Cardiff. (TV: Everything Changes)