In multi-level numbering this determines the level for this numbered or bulleted list. Lists of a lower level are reset by lists of a higher level. For example, a list at level 1 will reset a list at level 2, but a list at level 1 will not be reset by a list at level 2. A paragraph with no numbering will reset all lists.
Note: This outline level property applies to the Windows Help and HTML CCS style definitions as well.
The OutlineLevel element corresponds to the "Outline level" field, on the "Bullets and Numbering" sub-tab, on the "Style Definition" tab, of the Style object.