UDO knows which language and which document style you use.
Furthermore UDO knows if you are using indices or not. So UDO knows
enough to create the LaTeX preamble on its own.
How can I make files for LaTeX2e?
By default UDO saves files for LaTeX 2.09. If you use the switch
!tex_2e inside the preamble UDO will save a preamble and
other special commands for LaTeX2e.
I want to use a userdefined preamble!?
Use the switch !no_preamble [tex] inside the preamble of
your UDO source file and insert the userdefined LaTeX preamble into a
raw environment at the beginning of your UDO source file.
How can I use LaTeX formulas inside the text?
Use a raw environment for complete paragraphs or definitions for
floating text. An example:
!ifdest [tex]
!define ab2 $(a+b)^2 = a^2 + 2ab + b^2$
!else
!macro ab2 (a + b)^2 = a^2 + 2ab + b^2
!endif
...
The first binomial theorem: (!ab2)