-#define _STR_VOLUME_ID 0
-#define _VOLUME_STRS "RAM","NAND","CF","SD","SD2","USB","USB2","USB3"
-/* _STR_VOLUME_ID switches string support of volume ID.
-/ When _STR_VOLUME_ID is set to 1, also pre-defined strings can be used as drive
-/ number in the path name. _VOLUME_STRS defines the drive ID strings for each
-/ logical drives. Number of items must be equal to _VOLUMES. Valid characters for
-/ the drive ID strings are: A-Z and 0-9. */
+#define FF_STR_VOLUME_ID 0
+#define FF_VOLUME_STRS "RAM","NAND","CF","SD","SD2","USB","USB2","USB3"
+/* FF_STR_VOLUME_ID switches support for volume ID in arbitrary strings.
+/ When FF_STR_VOLUME_ID is set to 1 or 2, arbitrary strings can be used as drive
+/ number in the path name. FF_VOLUME_STRS defines the volume ID strings for each
+/ logical drives. Number of items must not be less than FF_VOLUMES. Valid
+/ characters for the volume ID strings are A-Z, a-z and 0-9, however, they are
+/ compared in case-insensitive. If FF_STR_VOLUME_ID >= 1 and FF_VOLUME_STRS is
+/ not defined, a user defined volume string table is needed as:
+/
+/ const char* VolumeStr[FF_VOLUMES] = {"ram","flash","sd","usb",...
+*/