Sometimes it is necessary, for a final version of a document, to
`help' LaTeX break the pages in the best way. LaTeX 2.09 had a
variety of commands for this situation:
etc. LaTeX2e provides, in addition, commands which can produce
longer pages as well as shorter ones.
These commands increase the height of a page (from its normal value of
\textheight) by the specified amount <size>, a rigid length. This
change affects only the current page.
This can be used, for example, to allow an extra line to be fitted onto the page or, with a negative length, to produce a page shorter than normal.
The star form also shrinks any vertical white space on the page as much as possible, so as to fit the maximum amount of text on the page.
These commands do not change the position of the footer text; thus, if a page is lengthened too far, the main text may overprint the footer.