confuse, not necessary, see how GC say:

來源: 於 2006-07-27 18:07:25 [舊帖] [給我悄悄話] 本文已被閱讀：次

in the back of the GC: "The person indentified by this card is authorized to work and reside in he U.S."

SSN: Valide to work only with DHS (INS) authorization.