Format menu

Copy Style
Paste Style
Clear Style
This commands clears all "local" style attributes from the current selection, that is, attributes that are set within the selection itself rather than attributes it is inheriting from a higher level.
Automatic Level Styles
While this is selected, OmniOutliner will automagically create level styles based on the way you style rows in each level. For instance, if you manually set every fourth-level row in your outline to be italic, the italic style will get promoted to the All level 4 rows style in the styles palette. Then any new rows you create at that level will have the same style.
Font
This sub-menu holds basic font style controls, which you can also access through the Appearance inspector. These commands work exactly as the equivalent commands on the inspector work.
Text
Show Ruler displays the ruler at the top of the document window.
Row Numbering
Use this sub-menu to define numbering for the selected text. Note that counts to create the line numbering will reflect the entire document.