Subcategories of idols include gravure idols (models who pose in pin-up-style swimsuit photographs), junior idols (singers and gravure models under the age of 15), AV idols (pornographic models),[33] net idols (idols who are mostly known for being Internet celebrities), idol voice actors (voice actors of anime and video games),[33][2] virtual idols (fictional singers created through programs such as Vocaloid), and underground idols (independently managed idol acts).