Represents the "H" entry of the fixed print dictionary object.

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

It contains a double representing a PDF numeric object.

The PDF specification states that this item assumes a value of 0 if no value has been provided.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 191, page 411.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 194, page 498.

The horizontal fraction between zero and one gives the position along the page width at which the annotation is anchored. Zero is the left edge; one is the right edge.