I'm creating a public form on a page that allows non-registered (public) visitors to create posts of a custom post type.
I'm using nonces, which I naiveley thought would expire once they were used. This doesn't appear to be the case.
This post seems to address the issue by creating a meta field and verifying that it doesn't exist before creating the post.
Is there a best practice that prevents double-form submissions (that doesn't require writing a meta field?)