Upper Eyebrows are the one you put your transparency map onto, and then set the transparency to 100%. This is also the one that dissapears when you use the BrowsGone morph. One of the others (can't remember which and I'm not at my Poser pc) is redundant and is not used. The other one is the one you set, colourwise, to use the texture you've used at the head, and the base colour here should be white (or whatever colour you used as base. As far as I remember the one at the bottom at the list is the redundant one. Same goes with the 2 EyeLashes/Eyelashes.

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.