Abstract: In document output including mixture of different sizes, regarding a paper (A4 size) which is not Z-folded, header/footor information is printed on the paper as a designated manner, and, regarding a paper (A3 size) which is to be Z-folded, the header/footor information is combined with document data in such a manner that the position of the header/footor information after Z-folding apparently becomes the same as the position of the information on the A4 size. For example, in an opened condition, two header/footor information are printed at two positions, and positions of two header/footor informations are adjusted so that an information component (99/1) printed on an area A and an information component (2/31) printed on an area D constitute one header information as “99/12/31”. As a result, the header/footor information can be recognized at a glance without opening the folded page, apparently similar to the non-Z-fold paper.