Attribute Data Type:
Attribute Default Value:
Attribute Inherited from Preferences?
Attribute First Added:
Number of outline levels between a note and the document root (read-only).
Actually, it is 1 + the number as 'top-level' notes have $OutlineDepth of 1, notes inside a top-level container have $OutlineDepth of 2, and so forth.
Aliases do not inherit this property from their original but have their own intrinsic value.