This message supports the snap-to-grid property, which aligns icons within grid squares whenever they are dragged and dropped inside the container.

param1
     PRECORDCORE  preccList  /*  Pointer to a linked list of container records to be repositioned in the grid. */

param2
     SHORT        xDrop      /*  X-coordinate of drop point expressed in desktop coordinates. */
     SHORT        yDrop      /*  Y-coordinate of drop point expressed in desktop coordinates. */