Represents the "MS" entry of the 3d view dictionary object.

It is an optional 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:.

• M
• U3D

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 304, page 521.

Adobe Supplement to the ISO 32000, BaseVersion: 1.7, ExtensionLevel: 3; Table: 9.39, page 57.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 344, page 707.

Adobe Supplement to the ISO 32000, BaseVersion: 1.7, ExtensionLevel: 3; Table: 9.51f, page 93.

The MS entry names the projection mode used for navigation: M for matrix (free transformation), U3D for U3D-compatible orbit navigation, and PAN for pan-and-zoom navigation.