Changed XML-Comment

Src/Newtonsoft.Json/MemberSerialization.cs

@@ -42,7 +42,7 @@ namespace Newtonsoft.Json
         OptOut = 0,
 
         /// <summary>
-        /// Only members must be marked with <see cref="JsonPropertyAttribute"/> or <see cref="DataMemberAttribute"/> are serialized.
+        /// Only members marked with <see cref="JsonPropertyAttribute"/> or <see cref="DataMemberAttribute"/> are serialized.
         /// This member serialization mode can also be set by marking the class with <see cref="DataContractAttribute"/>.
         /// </summary>
         OptIn = 1,
@@ -55,4 +55,4 @@ namespace Newtonsoft.Json
         Fields = 2
 #pragma warning restore 1584,1711,1572,1581,1580,1574
     }
-}
+}