Final answer:
The 10-code for returning to the fuels service center varies by department; commonly, 10-19 is used for 'return to station' but the exact code should be verified with the specific agency's list.
Step-by-step explanation:
In radio communication, particularly amongst law enforcement and other emergency services, 10-codes are used as shorthand signals to convey specific and common messages. One such 10-code that indicates an instruction to return to the fuels service center does not have a universally fixed number, as codes can vary by department or region. For example, one department might use 10-19 for 'return to station' or another code entirely for this purpose. It is essential to refer to the specific agency's 10-code list to find out their designated code for returning to the fuels service center.