Possible Clues:

• Sounds as if one is too nutty for command
• Essential part of officer's report?
• The edible centre of a nut
• Sounds as if he's rank and nutty
• At the core of the corps one is so nutty
• Ear item
• Inner part of a seed or grain
• What sailors are to boat here
• Seed in hard shell
• CO's speech in a nutshell