On May 26, 2004, the U.S. Patent and Trademark Office published rule changes that required applicants to use Customer Numbers if more than ten registered practitioners were to be made of record.
The rule change notice can be found here:
http://www.patentsusa.com/20040526_Power_of_Attorney.pdf
The rule changes were effective June 25, 2004.
The purpose of the changes was to reduce the processing burden on the office. The rule changes also eliminated associate power of attorney practice. The reasoning was that an associate power of attorney was not necessary for a patent practitioner to take most actions in a patent application. Instead of filing an associate power of attorney, a patent practitioner could instead file an "Authorization to Act in a Representative Capacity" after these rules changes.
Another change was that the Office discontinued the practice of returning patent and trademark assignment documents. Assignments would be scanned into the Office's electronic database. Because documents would no longer be returned, the rule changes eliminated original assignments from the list of documents that could be submitted for recordation.
If more than ten patent practitioners were named in a combined declaration and power of attorney (e.g., from an earlier filed application), applicants were to provide a separate paper indicating which ten were to be made of record. Then the Office of Initial Patent Examination would enter the practitioners listed on the separate paper. If more than ten attorneys were named and a separate paper was not provided, then no patent practitioners would be made of record. If a patent practitioner later attempted to sign a batch update request to request that the address associated with the Customer Number be used for correspondence, that request would be rejected because the patent practitioner was not of record. A newly executed power of attorney, or old power of attorney and separate paper listing ten practitioners would have to be provided.
