Related Clues:

• They keep 'Q' from 'U'
• V lead-in
• 18-20 in a sequence
• Q-U connection
• 18 through 20, in a run
• They're ahead of U
• Pre-U trio
• String after Q
• Alphabet section
• Four before V
• Q-U connectors
• Alphabet queue
• Queue past Q
• They may sneak up on U
• QU go-between