From DBCS OS/2 version 2.0, the system default font can be selected by end user from the Font Driver Object. This object is located in the System Setup folder of the System Folder. It is a notebook setup utility that provides the function to load/unload an MBCS raster font driver and sets up the new system default font. A user can select a default font from a list of MBCS fonts and select the face name and font size of the font. This font will become the system default font from the next IPL. The MBCS fonts that can be selected as the system default font are limited. Currently they are the fonts that are provided by the font driver PMNLSFD1.FDR and PMNLSFD3.FDR. See Font Drivers and their fonts in OS/2 J2.0 for font driver information.
Normally, the system default font of a DBCS PM after the system installation is set to 12 point in size. After that, depending on the end user's preference, they can be selected from various choices. So an application program must check the current font size even you do not change the font size in your program.