I was looking at the manual for the new Fishman Aura and it said it can be used with an undersaddle or magnetic soundhole pickup. What is the definition of undersaddle? Is it strictly pickups that sit directly under the saddle or does it include brideplate attached pickups as well?

Mario:
in my experience, undersaddle refers only to the piezo or similar pickups that are either imbedded in the actual saddle material (such as the Baggs LB6) or are laid under the saddle in the saddle slot (ie, Fishman, Baggs' ribbon transducer,Element, etc...) . Most now have on-board preamps in the jack, but a few don't. It is important to have an extremely high impedance on the input circuit if you are working with just the passive circuit as an input. That could be what they are referring to when they suggest compatability.
Other types of pickups which are actually under the bridge, but not the saddle, are referred to generically as soundboard pickups. Such as the McIntyre feather, the Seymour Duncan SA2, Baggs IBeam, etc..
Hope this helps.