Exporting an outline

Exporting is different from saving; it creates a new copy of your file on the disk, leaving the original file open on the screen. The new file will lose its OmniOutliner-specific formatting if it is exported in a different format.
Plain Text, Rich Text, and Apple Keynote export formats have settings in OmniOutliner's preferences which let you specify how to represent outlines in the exported format.
The available file formats are as follows:
OmniOutliner 3, OmniOutliner 3 Template, and OPML (Outline Processor Markup Language) are the same formats that are available when saving an outline.
OmniOutliner 2
Apple Keynote
Plain Text (fixed width)
Plain Text (with tabs)
Plain Text (MORE 3.1)
RTF (Rich Text Format)
RTFD (Rich Text Format with Attachments)
HTML (Dynamic)
HTML
HTML (MS Word)