An accessory device is provided with one or more physical interlocks for mating with a slot provided along an accessory mounting track, or alternatively, with discrete physical mating interlocking features provided along an accessory mounting track, such as along opposing sides of the slot. In this way, the accessory device can be mounted along the slot in a lengthwise direction of the accessory mounting track or perpendicularly or transversely to the lengthwise direction of the accessory mounting track. When mounting in a lengthwise direction of the accessory mounting track, the accessory device is prevented from moving along the accessory mounting track when sufficient frictional forces are applied. When mounting perpendicularly or transversely to the lengthwise direction of the accessory mounting track, the interlocks mate with the interlocking features to prevent movement of the accessory device along the accessory mounting track.