The definition and abbreviation for Potentially Hazardous Food (Time/Temperature Control for Safety Food) or PHF/TCS should be modified to drop the reference to potentially hazardous food and PHF.
Yes, as a treat apples are fine for chickens. Some will say it is best not to feed them too many apples as the seed of an apple has a small amount of arsenic in it.
Typically, backyard and small farm chickens also eat food scraps from the farm household - basically anything besides beans, garlic, raw potatoes, onions, and citrus. You can feed them beans, garlic, and onions but the eggs might taste funky. Raw potatoes can be poisonous to chickens.