%posttrans, %transfiletriggerin, and script ordering

Can anyone tell what exactly happens if an rpm transaction contains both calls to %posttrans and %transfiletriggerin? Is there any reliable order in which these scripts are called in the posttrans stage? Or putting it differently, is there any way to make sure the %posttrans script of package A runs after the %transfiletriggerin of package B, or vice versa? Regards Martin