The English version of the IOL problem sets are, once in a while, provided in two different versions, namely en(A) and en(B). Everyone assumes that the letters A and B stand for American and British variations of English language but what they stand for are never officially disclosed, presumably to circumvent the accusation of not taking countries other than the US and UK into considerations. Nonetheless, the differences between these two versions are minuscule and some people doubt why even we're having two separate versions. This article outlines the differences between the two versions in all the past problem sets from the IOL.
The date formatting for the contest date in the title section are different: mmmm d, yyyy in en(A) and d mmmm, yyyy in en(B). (e.g. August 2, 2019 in en(A) and 2 August, 2019 in en(B).
|2009||Problem 3 Burmese Names||mm/dd/yyyy||dd/mm/yyyy||in data; The only difference I think mattered|
|2011||Problem 4 Nahuatl||mom||mum||in data|
|2013||Problem 5 Telepathy||airplane||aeroplane||in data|
|2014||Problem 2 Kiowa||buffalo||bison||in data|
|Problem 4 Engenni||dialog||dialogue||in instructions|
|Problem 5 Northern Gbaya||center||centre||in question (c)|
|2015||Problem 3 Soundex||analyze||analyse||in instructions|
|Problem 5 Somali||meter||metre||in instructions|
|2019||Problem 3 Book Pahlavi script||sulfur||sulphur||in data|