Not to be confused with Vocagender
Vocagender or VOCALOIDgender is a gender directly tied to the VOCALOIDs that exist as avatars for voicebanks of the VOCALOID software. Being vocagender/VOCALOIDgender means that an indivdual feels that their gender is connected to or influenced by a certain VOCALOID or by VOCALOIDs in general. This gender may also be related to similar voice synthesizers or derivatives, such as FANLOIDs/Vocaloid Derivatives, UTAUs, or even possibly SynthesizerV vocals.
Akita Neru and Kasane Teto are not VOCALOIDs, despite often being confused for being so. They are a FANLOID and an UTAU, respectively.
Flags
The first flag represents Hatsune Miku, Kasane Teto and Akita Neru, a triad of voice synthesizers which sung in the classic VOCALOID song, "Triple Baka" by LamazeP.
An alternate flag has stripes representing Hatsune Miku, Kagamine Rin and Kagamine Len, KAITO, Megurine Luka, and MEIKO, who are the six Cryptonloids (VOCALOIDs produced by the company Crypton Future Media) and the six most well-known VOCALOIDs in general.
Another alternate flag was created by discord user zuos, on the 19th of September 2021. White represents the technological aspect of VOCALOID/the program itself, red represents the VOCALOIDs MEIKO & Fukase, yellow represents the VOCALOIDs Kagamine Rin & Len, blue represents the VOCALOIDs Hatsune Miku & KAITO, and purple represents the VOCALOIDs Flower & Camui Gackpo. The colors can also be associated with other Voice Synthesizers, if one wishes to do so.