For a SONE, this string isn't just code; it’s a portal to a specific moment in 2018 when they could watch their favorite idols with the clarity of a fresh English translation.
Including Yuri’s solo debut ( The First Scene ) which happened exactly around the "021018" date.
In October 2018, the Girls' Generation fandom was in a unique transition period. The subunit (comprising Taeyeon, Sunny, Hyoyeon, Yuri, and Yoona) had recently debuted with "Lil' Touch" in September.