Anatomy of the Dalek

 was a small pamphlet printed on Skaro for the use of Daleks going through "re-education training". Jeff Stone picked up a copy while sneaking around the city's so-called "Anatomy Room". It carried valuable, "Dalek-eyes-only" information about Dalek anatomy, which Stone was able to transport back to his human colleagues on Earth. (DWA: City of the Daleks)

Behind the scenes
The term  also describes the out-of-universe fold-out poster within The Dalek Book. The poster was meant to be what was inside the in-universe pamphlet, but since the reader could simply bypass the comic and pull the poster out of the book, it was also thought of as a standalone feature. From an out-of-universe perspective, it was the the first cross-sectional view of a Dalek that had ever been publicly released.