+\fIDEST_WIMFILE\fR does not yet exist, since if \fIDEST_WIMFILE\fR exists, the
+compression type must be the same as that of \fIDEST_WIMFILE\fR.
+.IP ""
+\fITYPE\fR may be "none", "maximum", or "fast". By default, it is the same as
+that of the input WIM file.
+.IP ""
+You may also specify the actual names of the compression algorithms, "XPRESS"
+and "LZX", instead of "fast" and "maximum", respectively.
+.TP
+\fB--threads\fR=\fINUM_THREADS\fR
+Number of threads to use for compressing data. Default: autodetect (number of
+processors). Note: multiple compressor threads are not very useful when
+exporting to a WIM with the same compression type as the source WIM, since
+wimlib optimizes this case by re-using the raw compressed data.
+.TP
+\fB--rebuild\fR
+When exporting image(s) to an existing WIM: rebuild the entire WIM rather than
+appending data to the end of it. Rebuilding the WIM is slower, but will save a
+little bit of space that would otherwise be left as a hole in the WIM. Also see
+\fB@IMAGEX_PROGNAME@ optimize\fR.
+.TP
+\fB--ref\fR="\fIGLOB\fR"
+File glob of additional WIMs or split WIM parts to reference resources from.
+See \fBSPLIT_WIMS\fR. This option can be specified multiple times. Note:
+\fIGLOB\fR is listed in quotes because it is interpreted by
+\fB@IMAGEX_PROGNAME@\fR and may need to be quoted to protect against shell
+expansion.
+.TP
+\fB--pipable\fR
+Build, or rebuild, \fIDEST_WIMFILE\fR as a "pipable WIM" so that it can be
+applied fully sequentially, including from a pipe. See \fB@IMAGEX_PROGNAME@
+capture\fR(1) for more details about creating pipable WIMs. The default without
+this option is to make \fIDEST_WIMFILE\fR pipable if and only if it already
+existed and was already pipable, or was "-" (standard output).
+.TP
+\fB--not-pipable\fR
+Build, or rebuild, \fIDEST_WIMFILE\fR as a normal, non-pipable WIM. This is the
+default behavior, unless \fIDEST_WIMFILE\fR already existed and was already
+pipable, or if \fIDEST_WIMFILE\fR was "-" (standard output).
+.SH SPLIT WIMS
+You may use \fB@IMAGEX_PROGNAME@ export\fR to export images from a split WIM.
+The \fISRC_WIMFILE\fR argument must specify the first part of the split WIM,
+while the additional parts of the split WIM must be specified in one or more
+\fB--ref\fR="\fIGLOB\fR" options. Since globbing is built into the \fB--ref\fR
+option, typically only one \fB--ref\fR option is necessary. For example, the
+names for the split WIM parts usually go something like:
+.PP
+.RS
+.nf
+mywim.swm
+mywim2.swm
+mywim3.swm
+mywim4.swm
+mywim5.swm
+.RE
+.PP
+To export the first image of this split WIM to a new or existing WIM file
+"other.wim", run:
+.PP
+.RS
+@IMAGEX_PROGNAME@ export mywim.swm 1 other.wim --ref="mywim*.swm"
+.RE
+.SH NOTES
+It is safe to abort an \fB@IMAGEX_PROGNAME@ export\fR command partway through;
+however, after doing this, it is recommended to run \fB@IMAGEX_PROGNAME@
+optimize\fR on the destination WIM to remove any data that was appended to the
+physical WIM file but not yet incorporated into the structure of the WIM, unless
+the WIM was being rebuild (e.g. with \fB--rebuild\fR), in which case you should
+delete the temporary file left over.
+.PP
+Since the WIM format uses single-instancing (streams are content-addressed by
+SHA1 message digests), when an image is exported, only the streams not already
+present in the destination WIM need to be copied. However, a new copy of the
+image's metadata resource always needs to be created.
+.PP
+.SH EXAMPLES
+Export the second image of 'boot.wim' to the new WIM file 'new.wim':
+.RS
+.PP
+@IMAGEX_PROGNAME@ export boot.wim 2 new.wim
+.RE
+.PP
+The above example creates "new.wim" with the same compression type as
+"boot.wim". If you wish to change the compression type, specify
+\fB--compress\fR=\fITYPE\fR; for example:
+.RS
+.PP
+@IMAGEX_PROGNAME@ export boot.wim 2 new.wim --compress=maximum
+.RE
+.PP