The policy applied almost universally within fandom is that, for the BBC Wales revival, any two episodes which air on consecutive weeks, are written by the same writer and are separated by a "To Be Continued" are part of the same story. Whilst this policy isn't definitive, and does support the classification of occasional three-part stories which have been stated by the writer not to be so, it is a less controversial starting point for TARDIS policy than what we have at the moment.