Picture this scenario: a homeowner of a magnificent apartment entrusts her residence to a new house manager. She shows him where the project manuals are located and wishes him good luck. The manager peruses the manual and finds some old construction documents to re-lamp a downlight in the living room. Light fixture “Type A” says recessed downlight. He sees that the light takes an MR16 lamp; he has heard of that before. He opens some drawers in the kitchen and finds one that is packed with a lot of lamps that were leftover from construction. With dusty fingers, from the construction-coated lamp box, he pulls out the trim, changes the lamp, and inserts it back in. Instantly the lighting design is ruined. Why?