Related Clues:

• Missive
• Scrimshaw material
• Do, for one
• Like a lofty tower
• Soap whose first slogan was "It floats"
• Form of a thank-you
• Marginal jotting
• Pay close attention to
• Short memo
• High C, for one
• Any letter from A to G
• Brief bit of correspondence
• Observe carefully
• It may stick around after the office closes
• Third of a triad