Possible Clues:

• Unimportant
• Petty officer, unsurpassed
• Petty case of sarcasm unsurpassed
• Petty officer and lieutenant hiding in a tree
• Insignificant
• Minor (colloq.)
• Insignificant and minute
• Piddling river from millstream formed
• Unimportant crook?
• Minor shopping centre covered by expresses on the way back