Why the confusion?
If "J" dimensions are not shown on a 180-degree hook, it is assumed standard ACI hooks are used. 2.3. Reinforcement Placement Tolerances aci 31518 pdf
If you need to calculate concrete pressure on forms, design form ties, or specify formwork tolerances, you want ACI 315-18. You need ACI 347-18. Keep reading to know how to get both legally. Why the confusion