Whether to detect and insert structure outline.
PDF document structure tags are analogous to header tags in
HTML: they allow one to structure document content as a hierarchy.
For example a document might be divided first by article then by
section then by chapter. There are specific named hierarchy types
available but in general an abstract hierarchical structure is all
that is required.
If this property is set to true, the AccessibilityOperation will
attempt to detect document structure and insert appropriate tags to
mark it as such.
If your documents are complicated and you require complete
control over the detection process, you can do this using the
techniques detailed in the AccessiblePDF example project which
comes with ABCpdf.