UDO expects a text file that you can edit with every ASCII editor. You should use only printable characters. That means you shouldn't use any characters below "space" except ASCII 9 (tab), ASCII 10 (line feed) and ASCII 13 (carriage return). A line of a source file shouldn't contain more than 512 characters.
UDO layouts the destination file itself. That means that it fills in spaces between words and lines between paragraphs:
You can compose the source file using different charsets. UDO supports the following character sets:
When UDO starts the conversion it excepts the character set that is used on the current operating system. If you want to convert source files that use characters from a different operating system you have to tell it to UDO by using the upper commands. Additional information can be found in the chapter "Special characters".