Borders, Citizenship and Immigration Bill [HL]

I rise to ask a question which is wholly incidental to these amendments. Is it a term of art or is there a matter of policy which causes in subsection (2)(c), "““the Secretary of State by whom general customs functions are exercisable””," to appear halfway through the list below a designated customs official or an immigration officer? These officers have been set out in a rather curious order, so as a matter of curiosity I am inquiring into whether there is a reason for it.