Only USB storage devices formatted in FAT16/32 formats support deleting files. You can find the deleted files in the "Hidden_" folder
The following types of USB devices may not be recognized or work correctly:-Encrypted MP3 players-USB devices not recognized as removable disks•A USB device may not be recognized depending on its condition.•Some USB devices may be incompatible with your system.•Depending on the USB device's type, capacity, or the format of files, USB recognition time may be longer.•Depending on the specification, some USB devices may not support charging via a USB connection.
Audio file specificationMPEG-1/2 Layer3, OGG (Vorbis), FLAC, WMA (Standard/Professional), WAVBit rates/Sampling frequencyMP38 to 320 kbps (CBR/VBR), to 48 kHz (ID3 tag version: Ver. 1.0, Ver. 1.1, Ver. 2.2, Ver. 2.3, Ver. 2.4)OGGQ1 to Q10, to 48 kHzFLAC8/16/24 bit, to 48 kHzWMA•Standard (0x161): to L3 Profile, to 385 kbps, to 48 kHz•Professional (0x162): to M0b, to 192 kbps, to 48 kHzWAV8/16 bit, to 48 kHzDetailed specifications•Maximum number of directory layers: 20•Maximum length of folder/file names: 255 byte•Supported characters for folder/file names: Alphanumeric characters, Korean standard character set 2,350 characters, Simplified Chinese 4,888 characters•Maximum number of folders: 2,000 (including ROOT)•Maximum number of files: 8,000