Editorial: avoid "The Type of" (tc39#3410)

spec.html

@@ -3147,7 +3147,7 @@ <h2>[[GetOwnProperty]] ( _P_ )</h2>
             The normal return type is either Property Descriptor or Undefined.
           </li>
           <li>
-            If the Type of the return value is Property Descriptor, the return value must be a fully populated Property Descriptor.
+            If the return value is a Property Descriptor, it must be a fully populated Property Descriptor.
           </li>
           <li>
             If _P_ is described as a non-configurable, non-writable own data property, all future calls to [[GetOwnProperty]] ( _P_ ) must return Property Descriptor whose [[Value]] is SameValue as _P_'s [[Value]] attribute.
@@ -3236,7 +3236,7 @@ <h2>[[OwnPropertyKeys]] ( )</h2>
             The returned List must not contain any duplicate entries.
           </li>
           <li>
-            The Type of each element of the returned List is either String or Symbol.
+            Each element of the returned List must be a property key.
           </li>
           <li>
             The returned List must contain at least the keys of all non-configurable own properties that have previously been observed.
@@ -15921,7 +15921,7 @@ <h1>[[OwnPropertyKeys]] ( ): either a normal completion containing a List of pro
             The returned List contains no duplicate entries.
           </li>
           <li>
-            The Type of each result List element is either String or Symbol.
+            Each element of the returned List is a property key.
           </li>
           <li>
             The result List must contain the keys of all non-configurable own properties of the target object.