Yorkshire Summary is the conventional description given to an appendix to the Domesday account of Yorkshire; the name does not appear in the text other than as an editorial insertion.
The Yorkshire Summary is, in effect, an index to the Domesday account of Yorkshire, listing only the Wapentake, vill, tax assessment, and tenant-in-chief of each holding. It is often classified as a satellite text.
The exact nature of its relationship to the Domesday text for Yorkshire has been the subject of considerable discussion, most recently by David Roffe, who argues that the Summary is earlier than the Domesday text and was used in its compilation. One of the most interesting recent observations about the Yorkshire Summary is that it is structured as a conversion table, making it easy to switch between geographically and feudally organised formats for Domesday Book.
For more detail, see H.B. Clarke, 'The Domesday satellites', Domesday Book: a reassessment, edited by Peter H. Sawyer (1985), pages 50-70; and David Roffe, Domesday: the Inquest and the Book (2000).