The official application to trademark the rights to 'Sechskies' was filed by YG Entertainment back in May of 2016. The application was approved approximately a year later, in April of 2017, according to KIPRIS (Korea Intellectual Property Rights Information Service). While 4 out of the 5 members of Sechskies decided to sign on with YG Entertainment in order to get back together after almost 7 years, according to a representative from YGE, "Because a group which does not include its original members is meaningless, the trade mark rights to the name Sechskies should rightfully belong to each of the members."
Trade mark rights registration for idol group names has become more prevalent in recent years due to the increased net worth of idols in the Hallyu wave. Reportedly, back in 1997, a trade mark rights registration for Sechskies's name was denied, likely due to the disposable nature of group names at the time. Similarly, another 1st-generation idol group g.o.d only obtained the trade mark rights to their group name in 2015.
Idol groups and their trade mark rights have also become a method for entertainment labels to pressure their artists during contract renewal periods, as seen in cases like B2ST or T-ara.