UDO doesn't support every command of the destination formats. If you need a special command you can add it by using definitions with parameters. You only need some knowledge about the destination format.
The following example shows how to write commands for changing the font size for LaTeX, HTML, Windows Help and RTF:
!code [iso] !docinfo [program] Changing the font size !docinfo [author] Dirk Hagedorn !docinfo [date] August 19th 1996 !ifdest [tex] !define tiny {\tiny{(!1)}} !define large {\large{(!1)}} !define Large {\Large{(!1)}} !define LARGE {\LARGE{(!1)}} !define huge {\huge{(!1)}} !define Huge {\Huge{(!1)}} !endif !ifdest [win,rtf] !define tiny {\fs14 (!1)} !define large {\fs28 (!1)} !define Large {\fs36 (!1)} !define LARGE {\fs44 (!1)} !define huge {\fs50 (!1)} !define Huge {\fs60 (!1)} !endif !ifndest [tex,win,rtf] !macro tiny (!1) !macro large (!1) !macro Large (!1) !macro LARGE (!1) !macro huge (!1) !macro Huge (!1) !endif !begin_document !maketitle !tableofcontents !node Test (!tiny [tiny]), normal, (!large [large]), (!Large [Large]), (!LARGE [LARGE]), (!huge [huge]) and (!Huge [Huge]). !end_document