Comment by hombre_fatal

So, it's a way to tell other applications how they would craft a URL on your site such that they can prefill a form on your site?

A meta tag in the html of your webpages seems like the wrong place for that info since it's not something that changes per page unlike the OpenGraph/TwitterCard meta tags that tell third-party apps how to generate a preview of the page.

Surely a better place would be example.com/.well-known/share-url.