When is a separate written request needed for PDX retrieval?

A separate written request for PDX retrieval is needed in two specific situations:

1. When the applicant wishes the Office to retrieve a foreign application from a foreign intellectual property office that becomes a participating office after the foreign priority has been claimed, as long as the time period set in 37 CFR 1.55 has not expired.
2. When the foreign application was not originally filed in a participating office, but a certified copy was filed in an application subsequently filed in a participating foreign intellectual property office.

The MPEP provides Form PTO/SB/38 for such requests:

Applicants can use Form PTO/SB/38 (Request to Retrieve Electronic Priority Application(s)) to file such a request.