Edit note: I've added in three answers for upvoting. This should cover all options without needing to downvote, but users are free to vote as they choose. As of this edit no moderator has commented, so there is no guarantee that there will be any outcome from this vote, but if there is a clear majority one way or another we can ask the moderators to consider the vote and take action.
The summary is that it is possible to have (currently) one of two banners, or no banner at all. The two banner options are:
- a reminder that AI-generated content is not permitted on our site
- a reminder that AI-generated content must be cited as such on our site
The advantage that I see of having a banner is that the policy is incontrovertibly visible to all would-be users of the site. Not having a banner doesn't mean we can't have a policy, but arguably having a policy that is less easy to find could lead to more frequent violations of it.
If there is a disadvantage to having a banner, it is likely that it might bring up more complaints that MSE is somehow 'hostile to newbies' which we seem to get every six months or so.
 Despite months of discussion just about everywhere I still see no evidence that a large language model is meaningfully AI and not just an expert-system with a large database and better hardware.