That language means that most likely you will be asked for an employment authorization document (EAD) or green card if you use the social security card as proof of your ability to work legally in the US. If its a brand new SSN, it may not yet turn up in credit searches or for selective service. If you are a green card holder, you can apply for a new card without that language on it.
www.gassonlaw.com - Disclaimer: This a general answer to your legal question. Unless you have a signed engagement letter with me, you should not consider this information to be legal advice.
What is your immigration status? If you are a permanent resident, then you may go to the social security administration and apply for a new card removing such annotation. The number will never change, they will just give you a new card without such language. If you are not a permanent resident or a US citizen, the language on your ss card means what it says AND you are NOT supposed to register in the selective service, reason why your ssn is probably not in their database as an eligible number.
This answer does not create an attorney-client relationship and should not be relied as legal advice on your case. You may call my office at (832) 305-5382 to schedule a consultation if you require specific legal advice. Law Offices of Hector J. Lopez. 1201 South Shepherd Dr. Houston, TX 77019. www.hjlopezlaw.com