From the 744 DDG (USA):
After engine start, EICAS Alert messages are the primary means of alerting the crew to non-normal conditions or improper configuration. Display of any Alert message requires accomplishment of the appropriate non-normal procedure by the crew. Upon completion of the procedure and prior to takeoff, the DDG should be consulted to determine if relief is available for continued operation with system faults displayed at the Alert Level.
So, we use engine start as the discriminator.