An advanced letter document class which extends LaTeX's usual
letter class, providing support for building your own
letterhead and marking fold points for window envelopes.
Options supported by the package include: letterpaper for US
letter; a4offset for a modified A4 layout suitable for platic
binders that cover a part of the left margin. The class's
handling of dates has inspired an extended version of date-
handling in the isodate package. The class supersedes an
earlier class called myletter.
