Mates in feature tree, New symbol

Hello,

I just recently switched from 2009 to 2011 version of SolidWorks.

I opened up an assembly I made in 2009 in the new 2011 and when I look at the mates in the feature tree, a new symbol appears nexts to the mate symbols.  It is an arrow pointing down at a green trimmed surface.

Can anyone tell me what this is?


Thanks

SolidworksAssemblies