Module AFHOUTAG contains the Unit Attribute Table defaults and DCB information for each I/O unit. You can accept the IBM-supplied defaults, shown in Figure 1, or you can supply your own defaults. To customize AFHOUTAG for your site, use the IBM-supplied job AFHWEUAT, and modify the AFHOUTCM, AFHOUNTM, and AFHODCBM macro instructions in an SMP/E USERMOD. The following sections describe the syntax and operands of the macro instructions.