Possible Clues:

• Bee lines?
• Poetry that doesn't rhyme
• Free for Limerick - blame the lineman for this
• The linesman is responsible for this free for Limerick
• "Paradise Lost" writing style
• "Paradise Lost" style
• Frost's 'Mending Wall' is written in it
• ''Paradise Lost'' form
• Much of Shakespeare's output
• Unrhymed poetry