I want a user to fill out a particular form and submit it, which changes a field on the order and saves it.

Right now, I have it so that the form sets a value in $order->data as a flag that the user filled out that particular form. My idea was that that could trigger an action in rules, which would then remove the flag and resave the order.

But it appears that rules doesn't have access to $order->data. Is that true? I'd prefer not to create a new field on my order just for this purpose.

I see in this post Ryan said something about a "custom rules condition" but I couldn't find instructions on how to do it.

http://drupal.org/node/1286430