concept page label in category itext
This is an excerpt from Manning's book iText in Action, Second Edition.
There are no references to page numbers in the page dictionary. Every page is self-contained and doesn’t care about the other pages in the page tree. The page number is determined by the order of the page dictionaries in the page tree. When walking through the page tree, the first page dictionary that’s encountered is the dictionary of page 1, the second of page 2, and so on. If you want to create page numbers for “human consumption”—for instance, i, ii, iii for pages 1 to 3, followed by 1, 2, 3 for pages 4 to 6—you can define page labels.
Figure 13.6 shows a PDF opened on page 3 of 10, but the page label says it’s page 1, because the first two pages in the page tree are labeled A and B. Starting with page 6 (labeled page 4), the page numbers get a prefix.
