There's a banner.sav flag in DSi cartridge header entry [1BCh], it's mentioned on http://dsibrew.org/wiki/DSi_Cartridge_Header since May 2011, but I've never found any info what the flag is doing, or if it's actually known to be used by any existing games. My theory would be that the banner.sav file might have same/similar format as the normal icon/title defined in cartridge header, but allowing to manipulate the icon (such like to indicate progress in the game, eg. if the game is crap, then the icon might change from a smiley to a sad face after some hours of playtime). Is that right? And are there any games doing such a thing? dsiwarehax seem to be also having 16Kbyte banner files. But I don't what they are good for: Maybe they are just meant to be put into SD card .bin header, or maybe they are also installed on eMMC for being shown in boot menu. Just copying that file to data\banner.sav in the sudoku folder doesn't seem to work though. Maybe it would work only if the cart header entry is flagged to use banners, and/or only if some flag in wrap.bin or system menu's .sav is indicating banner presence?