added to rdoc for unscope that default_scope wins

activerecord/lib/active_record/relation/query_methods.rb

@@ -340,6 +340,9 @@ module ActiveRecord
     #   User.where(name: "John", active: true).unscope(where: :name)
     #       == User.where(active: true)
     #
+    # This method is applied before the default_scope is applied. So the conditions
+    # specified in default_scope will not be removed.
+    #
     # Note that this method is more generalized than ActiveRecord::SpawnMethods#except
     # because #except will only affect a particular relation's values. It won't wipe
     # the order, grouping, etc. when that relation is merged. For example: