How do I format my custom html so wpautop won't try to reformat it?

How do I format my custom html so wpautop won't try to reformat it?

Great resource!
The question:
I've got a desktop app that generates html for my customers to paste into
their WP pages/posts. Nothing fancy just some image tags, hyperlinks and
simple inline css.
How do I preformat that code so wpautop won't try to re-format? What
triggers that function to add br and p tags? Are there any other tags it
will insert?
Thanks in advance.
Chris