An image data management apparatus which provides a pull-print mark for a file which is expected to be printed at an externally connected image forming apparatus, that is, to be subjected to pull-printing. It is possible to provide the pull-print mark for a plural number of files. When a user commands pull-printing of such a file at an externally connected image forming apparatus, a search is made within the files provided with the pull-print mark. Thereby, the load on the image data management apparatus for searching the file is light. In order to permit a user to command pull-printing at a printer with a simple user interface, simple authentication codes may be used.