[quote="gRomoZeka"]I agree, using 'во' "before words beginning with two consonants" is not a strict rile. There are hundreds of examples against it: в шкафу, в груди, в кресле, в правилах, в кровати, в словах, в клетке, в бреду, в драке, в строгости, etc.
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There must be ( somewhere ... ) a list of allowed consonant clusters, so that if "в**" cluster of 3 letters is allowed, it is allowed in any context, and there is no need of using "во" instead.