bmike Right now you can't do this. Since this is going to be a legal requirement in Europe soon, I would expect the Machform developers would add a new feature to address this somehow, but I certainly don't have any specific information that confirms that this will happen.
I would suggest that all Machform users in this forum who want this feature added as soon as possible should comment here to let the developers know. If you have an active support contract, you might want to contact the Machform developers directly.