If the Buffer Length value specified by the caller is smaller than the required storage for the pointer shape, the physical mouse device driver returns an error. The physical mouse device driver returns the minimum storage requirements for the pointer shape in the Buffer Length field.

If the Buffer Length value specified by the caller is greater than, or equal to, the amount of storage required for the pointer shape, the physical mouse device driver returns the pointer shape in the user's Pointer Shape buffer (that is, in the Data Packet) and the data describing the pointer shape in the Pointer Definition record (Parameter Packet). The actual returned length is returned in the Buffer Length field.