“I had a question asking about what situation does the PTO still investigate violotations of 37 CFR 1.56. I think the answer is in MPEP 1448”
1448 FRAUD, INEQUITABLE CONDUCT, OR DUTY OF DISCLOSURE ISSUES
The Office no longer investigates and rejects reissue applications under 37 CFR 1.56. The Office will not comment upon duty of disclosure issues which are brought to the attention of the Office in reissue applications except to note in the application, in appropriate circumstances, that such issues are no longer considered by the Office during its examination of patent applications.
…Form paragraph 14.21.09 should be used where the examiner becomes aware of a judicial determination of fraud, inequitable conduct or violation of the duty of disclosure on the part of the applicant independently of the record of the case, i.e., the examiner has external knowledge of the judicial determination. Form paragraph 14.22 should be used where, in the application record, there is (a) an explicit, unequivocal admission by applicant of fraud, inequitable conduct or violation of the duty of disclosure which is not subject to other interpretation, or (b) information as to a judicial determination of fraud, inequitable conduct or violation of the duty of disclosure on the part of the applicant. External information which the examiner believes to be an admission by applicant should never be used by the examiner, and such external information should never be made of record in the reissue application.