+showexec -- If set, the execute permission bits of the file will be
+ allowed only if the extension part of the name is .EXE,
+ .COM, or .BAT. Not set by default.
+
+debug -- Can be set, but unused by the current implementation.
+
+sys_immutable -- If set, ATTR_SYS attribute on FAT is handled as
+ IMMUTABLE flag on Linux. Not set by default.
+
+flush -- If set, the filesystem will try to flush to disk more
+ early than normal. Not set by default.
+