+.SS Example 3.
+Replace partition 2 of an image file, \fIA\fR, with a different
+file, \fIX\fR. For this example the partition table looks as follows.
+.RS
+\fB$ partx -oNR,START,SECTORS \fIA\fR
+ NR START SECTORS
+ 1 2048 2097152
+ 2 2099200 409600
+ 3 2508800 14268383
+.RE
+.br
+As each sector is 512 bytes the clipping points around partition 2 are
+1074790400 and 1284505600 and the insertion size is 209715200 bytes.
+The \fBfusefile\fR comman will therefore be as follows.
+.RS
+\fB$ fusefile -ononempty \fIA\fB \fIA\fB/:1074790400 \fIX\fB/:209715200 \fIA\fB/1284505600\fR
+.RE
+Note that the fused file shadows the original file \fIA\fR.
+
+.SS Example 4.
+Protect raw disk image file with an overlay:
+.RS
+\fB$ fusefile -ononempty disk.raw -overlay:today disk.raw\fR
+.RE
+By that set up, the overlay file, "today", will protect the disk image
+file, "disk.raw" from changes, and also override the pathname
+"disk.raw" to be the fused file.
+
+.SS Example 5.
+A fusefile mount with an \fIoverlay file\fR is writable regardless of
+the fused fragments, but all updates are written to the overlay file
+instead of to the fragments.
+
+.RS
+\fB$ fusefile -ononempty \fIA\fR \fB-overlay:\fIB\fB \fIA\fR
+.RE
+
+The overlay file, \fIB\fR in the example, contains all changes to the
+shadowed original file, \fIA\fR. The overlay file contains only the
+newly written regions and content is otherwise obtained from the
+original file.
+
+To that end, the overlay file also contains a "marker table" at the
+end as if appended to the fused file. That part of the file is outside
+of the fused file; and it's simply an element count followed by pairs
+of byte addresses that tell which regions of the fused file have been
+captured into the overlay file. (The marker table is of course
+maintained so that adjoining regions are collapsed)
+
+Thus, an overlay file may be reused to later re-establish the same
+fused file with overlay as previously, to continue capturing more
+changes.
+
+.SS Example 6.
+As final example, we set up a fused block device \fIy\fR as a swap of
+the beginning and end of file "x", at position 2442:
+.RS
+\fB$ sudo fusedisk -ouid=1000 y x/2442: x/:2442\fR
+.RE
+Note the use of \fBsudo\fR for becoming \fIroot\fR, which is required
+for block device handling, and also the \fB-ouid=1000\fR option so as
+to make the block device \fIy\fR be owned by the user with id 1000.
+