Q: FAQ: Manufacture ID Join Filter (Z-Stack, ZigBee)

Using the Manufacture ID to control/filter who joins a network.

You cannot use the manufacturing ID during the joining process to control whom is allowed to join the network because the only way to get this information is to request the User Descriptor (which can only happen between devices that are both joined to the network). However once joined, devices can request the User Descriptor of another device, and if a match is not found, ask the device to leave the network.