The file has been "decrypted," meaning the Nintendo 3DS encryption has been removed. This allows the game to be played on PC or Android emulators like Citra , rather than requiring a modified ("hacked") physical 3DS console.
Based on the file naming convention, refers to a specific, modified ROM file for the Nintendo 3DS game Etrian Odyssey Untold: The Millennium Girl . EOU-TMG-(UNDUB)-DecrTD-Ziperto.rar
If you're asking about this for technical or archival reasons, I can also explain: How to What the differences are between this and the original Where to find other similar modified ROMs The file has been "decrypted," meaning the Nintendo
Etrian Odyssey Untold: The Millennium Girl (EOU-TMG). This is a role-playing game developed by Atlus, combining dungeon crawling with a structured story mode. If you're asking about this for technical or
These types of files are used to experience the "definitive" version of the game, combining the best aspects of both localization and original audio, playable on alternative platforms.