Represents the "UF" entry of the related file set dictionary object.

It is an optional entry defined as part of the PDF 1.7 specification.

It contains an array which contains Elements.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; page 103.

The UF entry in a related file set maps the UF path key to an array of Unicode file path strings for related files under the Unicode path.