command-line option to
.BR mke2fs (8).
.TP
+.I auto_64-bit_support
+This relation is a boolean which specifies whether
+.BR mke2fs (8)
+should automatically add the 64bit feature if the number of blocks for
+the file system requires this feature to be enabled. The resize_inode
+feature is also automatically disabled since it doesn't support 64-bit
+block numbers.
+.TP
+ .I default_mntopts
+ This relation specifies the set of mount options which should be enabled
+ by default. These may be changed at a later time with the
+ .B -o
+ command-line option to
+ .BR tune2fs (8).
+ .TP
.I blocksize
This relation specifies the default blocksize if the user does not
specify a blocksize on the command line.