Classic Seven is a seven-room apartment floor plan one can find in buildings built in NYC prior to 1940 consisting of a formal dining room, a living room, a kitchen, three bedrooms, a maid's room, and two or more bathrooms. Classic Seven is essentially Classic Six with an added bedroom.
Layout
A maid's room is a must, and is located away from other bedrooms, almost always off the kitchen to allow maids of the past easy access. A typical maid's room also has a small bathroom attached to it.
References
Classic Seven Wikipedia(Text) CC BY-SA