Restore 3.0's definition of jurisdiction

Restored the definition of "jurisdiction" that was present in version 3.0.

Resolved #496

specification/gedcom-3-structures-3-meaning.md

@@ -1120,7 +1120,8 @@ A name given to a foundling orphan might be
 #### `PLAC` (Place) `g7:PLAC`
 
 The principal place in which the superstructure's subject occurred,
-represented as a [List] of jurisdictional entities in a sequence from the lowest to the highest jurisdiction.
+represented as a [List] of jurisdictional entities in a sequence from the lowest to the highest jurisdiction,
+where each jurisdiction is a unit in a political, ecclesiastical, or geographical hierarchy.
 As with other lists, the jurisdictions are separated by commas.
 Any jurisdiction's name that is missing is still accounted for by an empty string in the list.