37 CFR § 1.313 - Withdrawal from issue.
(a) Applications may be withdrawn from issue for further action at the initiative of the Office or upon petition by the applicant. To request that the Office withdraw an application from issue, applicant must file a petition under this section including the fee set forth in § 1.17(h) and a showing of good and sufficient reasons why withdrawal of the application from issue is necessary. A petition under this section is not required if a request for continued examination under § 1.114 is filed prior to payment of the issue fee. If the Office withdraws the application from issue, the Office will issue a new notice of allowance if the Office again allows the application.
(b) Once the issue fee has been paid, the Office will not withdraw the application from issue at its own initiative for any reason except:
(1) A mistake on the part of the Office;
(2) A violation of § 1.56 or illegality in the application;
(3) Unpatentability of one or more claims; or
(4) For an interference or derivation proceeding.
(c) Once the issue fee has been paid, the application will not be withdrawn from issue upon petition by the applicant for any reason except:
(1) Unpatentability of one of more claims, which petition must be accompanied by an unequivocal statement that one or more claims are unpatentable, an amendment to such claim or claims, and an explanation as to how the amendment causes such claim or claims to be patentable;
(2) Consideration of a request for continued examination in compliance with § 1.114; or
(3) Express abandonment of the application. Such express abandonment may be in favor of a continuing application.
(d) A petition under this section will not be effective to withdraw the application from issue unless it is actually received and granted by the appropriate officials before the date of issue. Withdrawal of an application from issue after payment of the issue fee may not be effective to avoid publication of application information.