prince-bookmark-label: none | content
content()
No
This property is used to determine the text content of the PDF bookmark generated by the current element.
Note that even though the initial value for this property is content(), no PDF bookmark will be generated by default as the initial value for the prince-bookmark-level property is none. See the documentation for PDF Bookmarks for more details.
Note that bookmark-label can be used as a shorthand for this property.