Outputs Overview When Mail Markup Pro has applied OMR marks to a PDF document, the mail piece(s) it contains must be output to a printer or to file. A Task must therefore have an output selected before it can be saved. Printer drivers available to the installation of Windows where Mail Markup Pro is installed appear as an output on the Outputs tab (Fig. 31). Fig. 31 Outputs tab By default, a print to file output also appears on the Outputs tab. This is used for creating one or more PDF documents (containing OMR marks) that can be printed at a later date using another application.