Usually used in Portugal, XPTO is somethig that dont make any logic sense at all.
XPTO was a greek definition of Christ, people used to read it like "xis–pê–tê–ó" to designate a excelent quality, divine, magnificent.
XPTO was also a guess from the 60's that one person had to cross a river and the person only had a note saying "XPTO" and the person should translate it to "despe-te e nada" (X=dez; P=pe; T=te; e 0=nada), that means undress and swim. Since them, XPTO is used as a synonym of something without any sence.
The word is from the greek Χριστός (Khristós)
You are XPTO!