Where an application, properly assigned to one Technology Center (TC), is found to contain one or more claims, per se, classifiable in one or more other TCs, which claims are not divisible inter se or from the claims which govern classification of the application in the first TC, the application may be referred to the other TC(s) concerned for a report as to the patentability of certain designated claims. This report is known as a Patentability Report (P.R.) and is signed by the primary examiner in the reporting TC.
Note that the Patentability Report practice is only to be used in extraordinary circumstances. See MPEP § 705.01(e).