An environment is a part of a source file that has to be converted in a special way. Environments will be started with !begin_ and finished with !end_. The commands have to be the first words of a line. They may be indented by spaces or tabs.
UDO offers you a large range of environments that will help you to layout your text and to insert special commands:
|center environment:||centered text|
|document environment:||documentation contents|
|flushleft environment:||left justified text|
|flushright environment:||right justified text|
|ignore environment:||ignore text|
|linedraw environment:||display graphic screenshots|
|preformatted environment:||preformatted text|
|quote environment:||indented text|
|raw environment:||special commands for the destination format|
|verbatim environment:||preformatted text|
|sourcecode environment:||source code|
In the relevant sections you can find out how the text of an environment is formatted.