VASSAL Reference Manual
A Player Hand is a specialized Private Window for containing a hand of cards. It is designated as belonging to a particular side or sides. The owning sides must correspond to one or more of the sides defined in the definition of player sides.
The main difference between a Player Hand and a normal Private Window is that in a Player Hand, a stack of pieces appears as a row.
Like a Private Window, a Player Hand can only be manipulated by the owning player, and can optionally be completely hidden from other players. Cards can be manipulated in the hand (turned face up, etc.) and can be rearranged in order. Cards can be dragged into and out of the window to add/remove them from the hand.
All other properties are the same as for an ordinary Map Window.
See sub-components for Map Window.