Those are the 7 imbalances that IM Jeremy Silman wrote about in his "How to Reassess Your Chess" and "The Amateur's Mind". Refering to minor pieces as officers is a little contrived to find a way to make the acronym work, but otherwise, that's a pretty good way to remember those 7 imbalances.
--Fromper
Got from chess lecture.com I=INIATIATIVE; M=MATERIAL, P=PAWN STRUCTURE,
L=LINES AND SQUARES, O=OFFICERS [BISHOPS-KNIGHTS], DE-DEVELOPMENT, S=SPACE, Use when finding candidate moves and analyzing your game.