Forefoot valgus, by definition, is a condition in which the forefoot is everted on the rearfoot when the subtalar joint is in it defined neutral position and the midtarsal joint is maximally pronated. It could be flexible or rigid depending on the range of motion at the midfoot joints.
http://www.podiatryabc.com/f-is-for-forefoot-valgus/ (Podiatry ABC)
http://www.podiatry-arena.com/podiatry-forum/tags/index.php?tag=/forefoot-valgus/ (Podiatry Arena)
http://www.podologiebucher.de/vorfus-valgus/152/ (Podiatry Books)
http://www.podiatry-arena.com/podiatry-forum/showthread.php?t=2624 (Podiatry Arena)