output (\fIWIMFILE\fR specified as "-"), and also for \fB@IMAGEX_PROGNAME@
append\fR, except when appending to a WIM that is already pipable.
.TP
-\fB--update-of\fR=[\fIWIMFILE\fR]:\fIIMAGE\fR
+\fB--update-of\fR=[\fIWIMFILE\fR:]\fIIMAGE\fR
Declares that the image being captured or appended from \fISOURCE\fR is mostly the same as
the existing image \fIIMAGE\fR in \fIWIMFILE\fR, but captured at a later point
in time, possibly with some modifications in the intervening time. This is
.IP ""
As shown, the full syntax for the argument to this option is to specify the WIM
file, a colon, and the image; for example, "--update-of mywim.wim:1".
-However, the WIM file may be omitted, in which case it will default to the WIM
-file being appended to for append operations, or the WIM file from which a delta
-is being taken (with \fB--delta-from\fR, if specified) for capture operations.
+However, the WIM file and colon may be omitted, in which case the WIM file will
+default to the WIM file being appended to for append operations, or the WIM file
+from which a delta is being taken (with \fB--delta-from\fR, if specified) for
+capture operations.
.TP
\fB--delta-from\fR=\fIWIMFILE\fR
For \fB@IMAGEX_PROGNAME@ capture\fR only: capture the new WIM as a "delta" from