Org. concerned with the word spelled by the starts of 18-, 24-, 36-, 54- and 59-Across 3 letters

Crossword clues for Org. concerned with the word spelled by the starts of 18-, 24-, 36-, 54- and 59-Across 3 letters

Answer	Clue
IRS	Org. concerned with the word spelled by the starts of 18-, 24-, 36-, 54- and 59-Across