Possible Clues:

• Common string that omits Q
• 7, on old phones
• Letters near 7, on some phones
• 7, on a phone dial
• Seven's former phone trio
• Twosomes: Abbr.
• Letters near the 7, on some phones
• Twosomes: Abbr
• Runner's best times (Abbr.)
• Phone trio before Q was added