Related Clues:

• 31-Across divs.
• Abbr. in ages
• Hist. book nos.
• Résumé abbr.
• Informative mtgs.
• Jr and Sr, in school
• '01, '02, etc.
• Long time: Abbr.
• Timeline info: Abbr.
• Jr. and sr., e.g.
• Millennium fractions (Abbr.)
• Mos. upon mos.
• Abbr. in old letter sign-offs
• Model information: Abbr.
• Sr. and jr.