WIsogloss
WBenrath line
WCastlecary
WCentum and satem languages
WHarthill, Scotland
WJireček Line
WJoret line
WLa Spezia–Rimini Line
WLandsker Line
WLinguistic boundary of Brittany
WSankt Goar lineWSpeyer line
WUerdingen line
WVon Wartburg Line
WWatford Gap