Board Thread:The Panopticon/@comment-1293767-20151029072618/@comment-1827503-20151029090754

RogerAckroydLives wrote: 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. There is precedent for non-consecutive weeks being a two-parter, but that was only a two-week gap between The Sontaran Stratagem and The Poison Sky, and the gap was not a deliberate production decision.

What there is not precedent for is a story sharing no elements with a traditional two-parter to be called a two-parter. Both A Good Man Goes to War and Let's Kill Hitler had previously-on segments, but unlike the traditional two-parters of the era, the previously recapped the entirety of Series 6 rather than the previous episode.

As a sidenote, Utopia had its next-time trailer after the credits similar to other two-parters, so it can be inferred that it is Part 1 of 3.