B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
B42D15/00—Printed matter of special format or style not otherwise provided for
B42D15/02—Postcards; Greeting, menu, business or like cards; Letter cards or letter-sheets
Sobre para envio de correspondencia,con ventana,con sobre de retorno de estilo para doblar,que tiene direccion de envio-a de retorno expuesta por el desprendimiento de la cubierta perforada