The show is consistent with the mechanics of address-dialing. The process involves associating a unique symbol of the inner ring to each of at least the first seven of the chevrons on the outer circumference. The main "address" is invariably dialed first, and the last symbol is the "point of origin", representing the gate being used, which acts as the final "send button" trigger for the completion of the address sequence. As each symbol is dialed, the chevron is said to "engage" or "encode" and usually responds by lighting up or moving. When the final symbol of an address is dialed, that chevron is said to "lock" and the wormhole opens (this terminology is arbitrary and often interchangeable, but preferred by the recurring character Walter Harriman). If the address is incorrect or does not correspond to an existing or otherwise functional stargate within that three-dimensional space, the last chevron will not lock, and all of the chevrons will "disengage".