How should a patent or application be identified in an assignment document?

According to 37 CFR 3.21 and MPEP 302.03, a patent or application should be identified in an assignment document as follows:

• For a patent: Use the patent number
• For a national patent application: Use the application number (series code and serial number, e.g., 07/123,456)
• For an international patent application designating the U.S.: Use the international application number (e.g., PCT/US2012/012345)
• For an international design application designating the U.S.: Use either the international registration number or the U.S. application number

For applications not yet filed or without an assigned number:

• For a non-provisional application: Identify by inventor name(s) and the title of the invention
• For a provisional application: Identify by inventor name(s) and the title of the invention

MPEP 302.03 suggests: “It is suggested, however, that an assignment be written to allow entry of the identifying number after the execution of the assignment. An example of acceptable wording is: ‘I hereby authorize and request my attorney, (Insert name), of (Insert address), to insert here in parentheses (Application number , filed ) the filing date and application number of said application when known.'”