There are a lot of hidden arguments that you can use that the Facebook API doesn't document. There are also undocumented properties of the FB object in JavaScri

There are a lot of hidden arguments that you can use that the Facebook API doesn't document. There are also undocumented properties of the FB object in JavaScript. This is especially true with fbml, which still lets you do some things the new API doesn't document. Just try to create an fb:request-form dynamically in a popup over flash - that's standard in many fb games and requires undocumented tricks.