Decalog was a series of short story anthologies published by Virgin Books.
Following the success of their New Adventures, Virgin Books launched the Decalog series in 1994 as a way to publish shorter Doctor Who fiction. The first three Decalog anthologies featured the first seven incarnations of the Doctor.
After Virgin Books lost its Doctor Who license in 1997, Decalog 4: Re:Generations concerned the family and history of New Adventures character Roz Forrester. Decalog 5: Wonders strayed even further from its origins, with most of its stories having no apparent connection to The Doctor Who universe.
BBC Books continued the Decalog format of multi-Doctor short stories by launching the Short Trips series of books, which was later taken over by Big Finish Productions.
Decalog 2: Lost Property
Decalog 3: Consequences
Decalog 4: Re:Generations
Decalog 5: Wonders