The package was designed as an extension of the lastpage
package -- as well as that package's LastPage label (created
\AtEndDocument) it adds a VeryLastPage (created
\AfterLastShipout). When more than one page numbering scheme is
in operation (as in a book class document with frontmatter),
the labels above do not give the total number of pages, so the
package also provides labels pagesLTS.<numbering scheme>, where
the numbering scheme is arabic, roman, etc. The package relies
on the undolabl package.