It was a badge one was to put on their profile that meant you didn't use vote trading services. There was a huge war over it that was unnecessary, and many words and actions were taken. In the end, many whales and others from the German community left when their voting strategies were compared to VTS and they were issued an ultimatum to take the IDUVTS tag off their profiles or they would not be receiving the upcoming airdrop for Game State. The tag was found offensive and coercive by many, and in times I discussed it I posited that it was no different than self voting. That people have the right to use their stake as they see fit, not as others decide they should be using it. True freedom of speech and property.
I left this comment almost a week ago on it.
https://blurt.blog/blurt/@practicalthought/r9x3w4
I've also written posts on it as it developed stating my opposition to those who would limit and label others for their use of personal stake if you are curious.