The machine readable line in the passport says P<D<<lastname<<oliver<middlename<<<<<

Note the single < between middle and first name. Maybe other countries code the sequence differently. My kids US passport say P<USAlastname<<first<middle<<<<


PS: also had a green card 2004-06 which I gave up. Also don't use any middle name or initial during the booking process for tickets to the US. ESTA and Global Entry have all the details and no one ever questioned anything.