You can read all in:
http://www.ins.gov/graphics/howdoi/faqeev.htm
Here is an interesting excerpt about the Social Security Card with restrictive text:
"Note also: It sometimes happens that an individual who satisfies I-9 requirements subsequently presents a restricted SSA card for payroll administration purposes (consistent with advice from SSA and IRS). Employers need not necessarily be concerned about this, since it is not unusual for an alien who is issued a restricted SSA card to proceed to permanent residence or even U.S. citizenship without applying to SSA to have the initial restrictions removed. "
http://www.ins.gov/graphics/howdoi/faqeev.htm
Here is an interesting excerpt about the Social Security Card with restrictive text:
"Note also: It sometimes happens that an individual who satisfies I-9 requirements subsequently presents a restricted SSA card for payroll administration purposes (consistent with advice from SSA and IRS). Employers need not necessarily be concerned about this, since it is not unusual for an alien who is issued a restricted SSA card to proceed to permanent residence or even U.S. citizenship without applying to SSA to have the initial restrictions removed. "