MPEP § fp15.50.02
A statement similar to the following should be used to describe the broken lines on the drawing (MPEP § 1503.02, subsection III):
-- The broken line showing of [1] is for the purpose of illustrating [2] and forms no part of the claimed design. --
A statement similar to the one above [3] inserted in the specification preceding the claim.
1. Do not use this form paragraph in an international design application.
2. In bracket 1, insert name of structure.
3. In bracket 2, insert --portions of the "article"-- or --environmental structure--.
4. In bracket 3, insert --must be-- or --has been--.