What I'm talking about is these tags which imply Nanashi Inc.:
and these tags which imply Vspo!:
Both of these agencies used to stick their VTubers into these distinct groups. For both the separation was very artificial, they didn't speak different languages or do significantly different activities as in some other cases. And both dissolved those subgroups, so now some of their members are left with this vestigial copyright tag that doesn't mean much.
I'm wondering whether anyone actually searches these tags. Take a look through the recent posts for both agencies - there's no agreement on whether they should be applied to new images of those characters. But even if they were applied consistently, whether only for pre-merge images or for all of them, I don't see them providing much real search utility. They would be better off recategorised to general and turned into group tags, for when all of their associated characters appear together. I've got some sample favgroups for that: favgroup #50522 (AniMare) & favgroup #50524 (LVG), and would gladly populate the rest.