The FORMAT line specifies the name of the page format in quotes, followed by the size in logical units of the physical page. The size of the physical page is the size within the margins. The logical units can be arbitrary integers. However, to avoid overflow, it is recommended that you not use large numbers.
An orientation is associated with the physical page size. This orientation describes the primitive page format orientation. The default is PORTRAIT. It can be changed to landscape by appending the keyword LANDSCAPE after the physical page size, separated by a comma. The primitive page format orientation should not be confused with the user-specified orientation, which is usually specified in the Print dialog box.