With Delta, I think it depends on the origin and destination. From major European and Japanese airports on Delta, I haven't run into this requirement, and I book for others using my card regularly. On other European airlines, however, I have, and in that case I haven't been able to book for others with a credit card. And there's been no way to do online check in when the requirement is in place. There's a warning at booking when this is a requirement, in my experience.