Stargate forcefield deactivation code

From The Stargate Omnipedia

Stargateforcefieldcode.jpg

Code used to deactivate the energy forcefield surrounding a Stargate that is protected by such a device. One such code was sent to the Alpha Site, and later used by teams from the S.G.C. to access the planet Erebus by deactivating its Stargate forcefield. Bra'tac had transmitted the code several months prior when he realized he had been captured on the planet, knowing that the S.G.C. base at the Alpha Site would record it.

KEY EPISODE

Orpheus - Jackson discerns the forcefield deactivation code to allow S.G. units to emerge on Erebus unharmed.