PLOT
Case File, marketed by BBC America as Yaz's Case File, was a series of webcasts released as a tie-in with series 11 of Doctor Who in 2018. It was scripted by Jacqueline Rayner.
As the BBC America name implied, they were a mini-recap of the episodes but from Yasmin Khan's perspective. As such, they contained little new information that wasn't already obvious to the viewer of the main Doctor Who episode.
The series was similar in format to Monster Files, seen during the late RTD/early Moffat era. It also shared some commonality with Sarah Jane's Alien Files that was released with The Sarah Jane Adventures for a time — although that series had more content that was not seen in the accompanying episode.
The series stood in contrast to Tardisodes and prequels, two types of short-form programming that offered wholly new narrative rather than explorations of concepts and creatures already featured in televised stories.