vfat in mount of msdos file system

[Douglas Bates <dbates@stats.adelaide.edu.au>]

I have checked the man page for 'mount' and the Linux FAQ and even
looked for an info page for 'mount' and I still can't find any
references to 'vfat'.

I have a disk partition with Windows NT on it.  If I mount that
partition with

 mount -t msdos /dev/hda1 /dos

I get periodic kernel messages about vfat directory entries.  A sample
message is

 Feb 26 06:43:28 arcola kernel: MSDOS-fs warning: vfat directory entry found on fs mounted non-vfat (device 03:01)

As far as I can tell vfat indicates the extensions to the DOS file
allocation tables that Windows 95 and Windows NT use for their long
file names.  A little browsing in /usr/src/linux/fs/filesystems.c
shows that there is code that knows about vfat but I can't see whether
one uses an keyword option in 
 mount -t msdos ...
or one tries
 mount -t vfat ...

As I would prefer not to play "guess how the software runs" when I am
dealing with entire file systems, I would appreciate any suggestions
of where to look for documentation on this.

-- 
Douglas Bates             Dept. of Statistics, U. of Wisconsin-Madison
            (visiting at: Dept. of Statistics, U. of Adelaide)
   bates@stat.wisc.edu    or   dbates@stats.adelaide.edu.au