In reply to Duncan_S:
It describes the face fabric. W.L. Gore Ltd produce hundreds of different fabrics, and most companies don't bother naming each one because it would confuse poor punters like you (point proven). Very few companies (Arc'Teryx are probably top of the list) use a face fabric, made to their own specifications. Everyone else just use off the shelf materials.
BTW it is standard 3-layer Gore-Tex (or rather Performance Shell). Hence not very expensive.