Where is one flying from? A dinner jacket may be worn, but be weary of it identifying one if one is a bulkhead feet user as the FT Paparazzi are always keen to humiliate on these hallowed walls. Don't forget to buy a seat for your butler and chauffeurs, and ensure they have got airside clearance for your journey; it is helpful if you are head of state of a small country to appease the officials that this is necessary and the can bring the motorcade to doors 1L. As for greetings and routings, one must never speak to the hire help, so hopefully your executive PA will sort all that for you without needing to resort to DYKWIA.