Since the creation of Kasane Teto (SV), Danbooru has had two different qualifiers for Synthesizer V - the older (synthesizer_v) and the newer (sv). Nominally speaking, their distinction is that the former is for stuff made with the software (songs) or vocal synths made specifically for it (characters), while the latter is for non-original vocal synths receiving a Synthesizer V version. There was also (synthv) as a qualifier but that one got hunted into extinction.
But is that distinction actually the case? Per something like topic #31079, Uni (Vocaloid) has the qualifier Uni (Synthesizer V) for her SV version, and who knows how many mismatching cases we have.
So do we want to formalize this two-qualifier system for Synthesizer V, or should we standardize everything to be under (synthesizer_v), the larger (in use) of the two qualifiers?