Represents the "S" entry of the media criteria dictionary object.

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

It contains a bool representing a PDF boolean object.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 268, page 489.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 279, page 614.

The S entry holds an array of subtypes identifying acceptable rendering technologies. The rendition is accepted only if one of the listed rendering engines is available.