Historical clue formulations

• Small area measurement: Abbr. — 2024-04-15
• Ad space meas. — 2018-01-11
• Abbr. in many an area measure — 2017-09-08
• Newspaper ad meas. — 2013-12-04
• 1/64 of a checkerboard, maybe: Abbr. — 2008-01-17
• Area meas. — 2000-11-22