A# on opt card

[kkk_123]

My husband and I are filing documents for my Green Card. I am currently on OPT . All this while, I was told that F1 non-immigrants have no alien registration number. Is the A # (9 digits) on my OPT card the Alien Registration Number? Also, is this the number I have to fill on certain sections of the forms? I have heard of USCIS assigning a different number once the application is approved or received. I need advice. Help!

Thanks

[kabkaba]

You can write the same A number. It is not a big deal.