Returns or sets the starting heading level for a table of contents or table of figures. Corresponds to the starting value used with the \o switch for a TOC (Table of Contents) field. Read/write Long.
Remarks
Use the LowerHeadingLevel property to set the ending heading level. For example, to set the TOC field syntax {TOC \o "1-3"}, set the LowerHeadingLevel property to 3 and the UpperHeadingLevel property to 1.