In accordance with 14 CFR 91.141, Flight Restrictions in the Proximity of the Presidential and Other Parties, United States Secret Service (USSS) and FAA establish temporary Flight restrictions (TFR) via NOTAM requiring all aircraft operating within the designated TFR to squawk a discrete code prior to departure and at all times while in the TFR.  USSS will no longer grant TFR waivers to allow aircraft operations within the TFR without operational transponders; all aircraft will be required to squawk a discrete code while in the TFR.