Possible Clues:

• Roger, at times
• Overlord, for the Battle of Normandy
• Secret term for a military operation
• Line holding up outstanding puzzle
• L = Lima, e.g.
• Perhaps Juno will have firm date by start of Easter term
• Pacifist and Duke quarrelled over secret series of letters
• It may not mean what you think
• Poem with cracking line that's quoted in secrecy?
• Key to an encipherment