This property stores the filename of the image of the manga cover used on the Volume's page. This uses text values.
Y
OS01-PromoJP.png +
OS02-PromoJP.png +
YA01-PromoEN.png +
YA02-PromoEN.png +
YA03-PromoEN.png +
YA04-PromoEN.png +
YA05-PromoEN.png +
YA06-PromoEN.png +
YA07-PromoEN.png +
YG01-PromoEN.png +
YG02-PromoEN.png +
YG03-PromoEN.png +
YG04-PromoEN.png +
YG05-PromoEN.png +
YG06-PromoEN.png +
YG07-PromoEN.png +
YG08-PromoEN.png +
YG09-PromoEN.png +
YR01-PromoEN.jpg +
YR02-EN.jpg +