Determining which pages have changed

The following method is used to determine if a page is included in the list of changed pages:

  • the page identifier for the page is determined. If the page has no page identifier it is included.

  • the page in the previous release with the same page identifier is found. If there is no such page in the previous release, the page is included;

  • if the corresponding page in the previous release exists, but is on a different side of the leaf, the page is included; otherwise

  • the two pages are compared. If a change is identified within the difference area, the page is included.

In addition, the page can be included because of a derived change:

  • if the page is on the same leaf as a changed page (for example, if the front of the leaf is unchanged, but the back is different — the front must also be issued);

  • if the page is in the same group as a changed page.