Represents the "S" entry of the rendition dictionary object.

It is a required entry defined as part of the PDF 1.0 specification.

It contains a string representing a PDF name object.

This item may take one of the following valid values:.

• MR
• SR

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 266, page 489.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 277, page 613.

The S entry names the rendition subtype: MR for a media rendition that directly references media content, or SR for a selector rendition that holds an ordered list of candidate renditions.