a real world point of view
Virgin Books, or Virgin Publishing, was the book publishing arm of Virgin Enterprises which published licensed Doctor Who fiction and non-fiction during the early-to-mid 1990s. Under the Doctor Who Books imprint, Virgin published the Doctor Who New Adventures and Missing Adventure novels, as well as the Virgin Decalogs anthologies and Licence Denied (a collected anthology of fan writing edited by Paul Cornell).
With the show's return in 2005, Virgin published an unofficial reference book Who's Next: An Unofficial and Unauthorised Guide to Doctor Who.
In 2007, a decade after they stopped publishing official Doctor Who material, Random House gained majority shareholding, effectively ending Virgin's life as an independent publishing company. Like BBC Books, it now exists as an imprint in the Ebury Publishing division.
Logos EditThe New Adventures and other Doctor Who tie-in books and merchandise focusing on the Seventh Doctor era generally used the Seventh Doctor's logo as seen on television. Virgin also created an exclusive version of the classic "diamond logo" for use on the Missing Adventures and other material focusing on the eras of then-past Doctors.
However, the Virgin logo itself was rarely, if ever, used on any Doctor Who output. This is most likely because the books were published under the "Doctor Who Books" imprint.