Canfield solitaire: moving partial sequences
Bicycle cards lists the more restrictive rule.

Building
Any movable card or cards (from tableau, reserve, or stock) may be placed only on a card next-higher in rank and of opposite color in the tableau. Example: The  8♥ may be placed on  9♣ or  9♠. An entire pile of the tableau must be moved as a unit.

Boardgames.about.com also lists the more restrictive rule.
To move cards from one tableau pile to another, you may only move the entire pile.