From IRS.

"A corporate officer and an electronic return originator (ERO) use this form when the corporate officer wants to use a personal identification number (PIN) to electronically sign a corporation’s electronic income tax return and, if applicable, consent to electronic funds withdrawal. Form 8879-CORP is used for electronic signature authorizations for Form 1120, U.S. Corporation Income Tax Return; Form 1120-F, U.S. Income Tax Return of a Foreign Corporation; or Form 1120-S, U.S. Income Tax Return for an S Corporation."