Flatness with Datum Targets

In this Question Line video, Jason answers the following questions regarding datum targets and flatness, also discussing profile of a surface. 

 

1. I would like to know how to apply a Flatness or Profile tolerance to Datum Targets. If I have 3 points of contact/targets to define Datum A, how would I apply a Flatness/Profile to these targets?
2. Also would like to know if every datum must be a target, or can I mix and match? Can I use targets to define 3 points of contact for Datum A, and then use a midplane datum for B?

 

Jason walks through the drawing below explaining that flatness is not applied to the datum targets themselves, and why it must be applied to the surface if a flatness control is desired. 

 

 

Jason also answers the second question discussing datum target areas and profile of a surface using the below drawing: 

 

 

 

 

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