pnew("subpage") in fortran
Subpages are the smallest entity - they can contain one chart, e.g. contours superimposed on a background map of coast lines and grid lines.
A geographical projection or cartesian transformation is always attached to a subpage.
One or more subpages can be plotted on a page, provided that they fit within the limits assigned to that page.
Subpages can be of varying sizes.
A subpage is defined by the position of its bottom left hand corner and its lengths in the horizontal (X) and vertical (Y) directions in cm.