Generalized learning rules may be implemented. A plurality of channels are monitored to determine which channels are available for communications. A head cover made of the same fabric provides concealment for the user’s head. If the authentication is unsuccessful, on the other hand, the device may be maintained in a locked state with regard to the selected level of access. The pockets between adjacent carrier bars are open and able to receive the articles when the adjacent carrier bars are at the non-linear path portion, and are closed and tightly grasp the articles when the adjacent carrier bars are at the substantially linear path portion.