I own a website where people create things and embed it on their website. Let's call it "mysite.com".
A user can create a page like "mysite.com/1" and embed it on their website, "acceptable.com". How can I prevent some other site like "forbidden.com" from being able to display "mysite.com/1" in an iframe?
tl;dr How can I make a "whitelist" for sites trying to iframe my own site?