Possible Clues:

• Is unobliged to
• Can refuse to
• Thelonious Monk's 'Well You ___'
• Negative contraction
• Don't have to
• Does not have to be in short (5'1)
• ''You __ bother''
• 'You -- worry' ('It's OK')
• 'You -- bother'
• Have no requirement to