Possible Clues:

• For K thru H.S.
• For grades 1-12, in brief
• Software mkt. category
• Regarding grades K-12, for short
• Precollege level
• It accounts for twelve years of schooling, briefly
• Of grades 1-12, briefly
• Like many textbooks: Abbr.
• Half of New Delhi
• Relating to grades 1-12