Represents the "Prev" entry of the cross-reference stream dictionary object.

It is defined as part of the PDF 1.0 specification.

It contains an integer representing a PDF numeric object.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 17, page 50.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 17, page 65.

The Prev entry gives the byte offset of the previous cross-reference section or stream, serving the same role as Prev in a traditional trailer dictionary. It enables traversal of all revisions in an incrementally updated document.