To use a laymen analogy, the yellow pages remove your friend Jimmy's phone number from the phone book, now no one can call him. You already couldn't call him anyways because your parents don't let you use the phone. Now the yellow pages have been updated and have Jimmy's number again, you get one of the first copies, you can now see Jimmy's number, you still can't call him because you live in a strict Chinese household that doesn't let you freely use the phone, but his number is once again in the phone book and you at least can verify that.