IPC/WHMA-A-620 - Revision A - Addendum with Amendment 1 - Space and Military Space Applications Electronic Hardware Addendum to IPC/WHMA-A-620A Document #: IPC/WHMA-A-620 Revision A Product Type Addendum with amendment(s) Released: 06/01/2012 Language English Space Applications Electronic Hardware Addendum to IPC/WHMA-A-620A. When specifically required by procurement documentation, this Addendum supplements or replaces specifically identified requirements of IPC/WHMA-A-620, Revision A.