+.TP
+\fB--threads\fR=\fINUM_THREADS\fR
+Number of threads to use for compressing data. Default: autodetect (number of
+processors). Note: if exporting to an uncompressed WIM, or exporting to a WIM
+with the same compression type as the source WIM, additional threads will not
+be used, regardless of this parameter, since no data compression needs to be
+done in these cases.
+.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.