Overtime or shiftwork is optional for an apprentice under 18: they cannot be directed to do it. Except in an emergency, no apprentice may be rostered or directed onto overtime or shiftwork that would clash with attendance at a Registered Training Organisation that any law, award or regulation requires. Clause 22.4 repeats the overtime limb.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.