Possible Clues:

• Short sentence adopted as rule of conduct
• Catch-phrase
• Phrase on family arms
• "All for one and one for all," e.g.
• Saying something clever before telephone operator starts
• Below the crest it's grand to go backwards and forwards
• E pluribus unum, for one
• Low about race slogan
• Saw maiden, sober, in pair of spectacles
• 'Live Free or Die,' for New Hampshire