DW
From TARDIS Index File, the free Doctor Who reference.
The prefix DW indicates a Doctor Who Universe (Whoniverse) story aired on the Doctor Who television program itself or as a Doctor Who television special. It excludes all other forms of media in which Doctor Who stories have appeared.
Other Doctor Who Universe stories have appeared in the K-9 and Company special and on the television series Torchwood and The Sarah Jane Adventures. These have their own abbreviations.
