MK

1. Macedonia (IVR)
2. Mark (of cars)

Mk

1. Mark (German currency)
2. Markka (Finnish currency)

• usedn't
• used-up
• useful
• useful arts
• useful life
• useful lives
• useful load
• useful loads
• usefully
• usefulness
• usefulnesses
• useless
• uselessly
• uselessness
• uselessnesses
• Usenet
• usen't
• user
• user-friendly
• user ID
• user IDs
• user interface
• user interfaces
• username
• usernames