IOS254 is commonly used for various purposes:
- BootMii as an IOS, is installed to this slot.
- PatchMii uses this as a temporary IOS.
- System Menu 3.4 included a copy of IOS9 as IOS254 to block PatchMii (and maybe to break some pirate tools), but Nintendo replaced the wrong IOS number, since most pirate tools use IOS249. Everytime that IOS9 was updated, IOS254 was updated also.
- The 4.3 update included a Stub IOS in this slot, in an attempt to overwrite BootMii/IOS, but if failed, because the version number wasn't high enough. This was also done in order to reduce the number of IOS branches having to be maintained.