A word's stem for matching: words of 5 letters or more lose one common ending ("training", "trained" → "train"); shorter words and codes ("AR", "CPT") match as written, so "AR" never matches "are".
A word's stem for matching: words of 5 letters or more lose one common ending ("training", "trained" → "train"); shorter words and codes ("AR", "CPT") match as written, so "AR" never matches "are".