msdosfs(5): Explain how to determine version of the FAT file system.

While here, remove deprecated Tn macros.

Reviewed by:	bcr
Approved by:	re (gjb), krion (mentor)
Sponsored by:	Bally Wulff Games & Entertainment GmbH
Differential Revision:	https://reviews.freebsd.org/D17237

share/man/man5/msdosfs.5

@@ -2,7 +2,7 @@
 .\" Written by Tom Rhodes
 .\" This file is in the public domain.
 .\"
-.Dd October 1, 2013
+.Dd September 27, 2018
 .Dt MSDOSFS 5
 .Os
 .Sh NAME
@@ -15,9 +15,7 @@ The
 .Nm
 driver will permit the
 .Fx
-kernel to read and write
-.Tn MS-DOS
-based file systems.
+kernel to read and write MS-DOS based file systems.
 .Pp
 The most common usage follows:
 .Pp
@@ -43,9 +41,7 @@ that looks similar to:
 /dev/ada0sN		/dos	msdosfs		rw	0	0
 .Ed
 .Pp
-This will mount an
-.Tn MS-DOS
-based partition at the
+This will mount an MS-DOS based partition at the
 .Pa /dos
 mount point during system boot.
 Using
@@ -58,6 +54,15 @@ See
 for more information on
 .Fx
 directory layout.
+.Sh EXAMPLES
+Determine which FAT file system version (e.g, FAT16, FAT32)
+is a partition formatted with:
+.Bd -literal -offset indent
+file -s /dev/da0s1
+.Ed
+.Pp
+.Xr gpart 8
+may also be used to extract this information.
 .Sh SEE ALSO
 .Xr mount 2 ,
 .Xr unmount 2 ,