Represents the "CropBox" entry of the box colour information dictionary object.

It is an optional entry defined as part of the PDF 1.0 specification.

It contains a BoxStyleElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 360, page 630.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 396, page 810.

The CropBox entry references a box style dictionary specifying the color and line style for the crop box guide in a page editing application.