FAT, exFAT and Windows refuse < > : " | ? * in a name (fs/fat/namei_vfat.c:201-207, fs/exfat/nls.c:396-403). RetroDECK's component manifest names zxs:48.rom, zxs:if1-2.rom and snes:st018.data.rom: on an exFAT card each write failed with EINVAL on every run. The installer now probes the BIOS folder as keeps_case does, leaves those entries out and names them.