diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index ffae7b3..f7d6a03 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -248,7 +250,19 @@ DOTypeNameCompare(const void *p1, const void *p2)
 	if (cmpval != 0)
 		return cmpval;
 
-	/* To have a stable sort order, break ties for some object types */
+	/*
+	 * To have a stable sort order, break ties for some object types.  Most
+	 * catalogs have a natural key, e.g. pg_proc_proname_args_nsp_index.
+	 * Where the above "namespace" and "name" comparisons don't cover all
+	 * natural key columns, compare the rest here.
+	 *
+	 * The natural key usually refers to other catalogs by surrogate keys.
+	 * Hence, this translates each of those references to the natural key of
+	 * the referenced catalog.  That may descend through multiple levels of
+	 * catalog references.  For example, to sort by pg_proc.proargtypes,
+	 * descend to each pg_type and then further to its pg_namespace, for an
+	 * overall sort by (nspname, typname).
+	 */
 	if (obj1->objType == DO_FUNC || obj1->objType == DO_AGG)
 	{
 		FuncInfo   *fobj1 = *(FuncInfo *const *) p1;
@@ -312,13 +326,16 @@ DOTypeNameCompare(const void *p1, const void *p2)
 		CollInfo   *cobj2 = *(CollInfo *const *) p2;
 
 		/*
-		 * Sort by encoding, per pg_collation_name_enc_nsp_index.  This is
-		 * mostly academic, because CREATE COLLATION has restrictions to make
-		 * (nspname, collname) uniquely identify a collation within a given
-		 * DatabaseEncoding.  pg_import_system_collations() bypasses those
-		 * restrictions, but pg_dump+restore fails after a
-		 * pg_import_system_collations('my_schema') that creates collations
-		 * for a blend of encodings.
+		 * Sort by encoding, per pg_collation_name_enc_nsp_index.  Wherever
+		 * this changes dump order, restoring the dump fails anyway.  CREATE
+		 * COLLATION can't create a tie for this to break, because it imposes
+		 * restrictions to make (nspname, collname) uniquely identify a
+		 * collation within a given DatabaseEncoding.  While
+		 * pg_import_system_collations() can create a tie, pg_dump+restore
+		 * fails after pg_import_system_collations('my_schema') does so.
+		 * There's little to gain by ignoring one natural key column on the
+		 * basis of those limitations elsewhere, so respect the full natural
+		 * key like we do for other object types.
 		 */
 		cmpval = cobj1->collencoding - cobj2->collencoding;
 		if (cmpval != 0)