Just thought I'd weigh in here. We [or at least I] are [am] not saying Afghan is incorrect. I actually use Afghan and would not use Afghani or Afghanistani. But there's a source for Afghanistani, so don't we have to include it as well? I really don't think WP is supposed to be normative; if that's false, please direct me to the policy. The version which I want to see includes all three demonyms, with sources, and Afghan listed first.