-On Windows: Fail immediately if the full security descriptor of any file or
-directory cannot be set exactly as specified in the WIM file. The default
-behavior without this option is to fall back to setting a security descriptor
-with the SACL omitted, then only the default inherited security descriptor, if
-we do not have permission to set the desired one. On UNIX: with
-\fB--unix-data\fR, fail immediately if the UNIX owner, group, or file mode on an
-extracted file cannot be set for any reason.
+Fail immediately if the full security descriptor of any file or directory cannot
+be set exactly as specified in the WIM file. On Windows, the default behavior
+without this option is to fall back to setting a security descriptor with the
+SACL omitted, then only the default inherited security descriptor, if
+\fB@IMAGEX_PROGNAME@\fR does not have permission to set the desired one. Also,
+on UNIX-like systems, this flag can also be combined with \fB--unix-data\fR to
+cause \fB@IMAGEX_PROGNAME@\fR to fail immediately if the UNIX owner, group, or
+mode on an extracted file cannot be set for any reason.
+.TP
+\fB--include-invalid-names\fR
+Extract files and directories with invalid names by replacing characters and
+appending a suffix rather than ignoring them. The meaning of this is
+platform-dependent.
+.IP "" 6
+On POSIX-compliant systems, filenames are case-sensitive and may contain any
+byte except '\\0' and \'/', so on a POSIX-compliant system this option will only
+have an effect in the unlikely case that the WIM image for some reason has a
+filename containing one of these characters.
+.IP "" 6
+On Windows, filenames are case-insensitive, cannot include the characters '/',
+\'\\0', '\\', ':', '*', '?', '"', '<', '>', or '|', and cannot end with a space
+or period. Ordinarily, files in WIM images should meet these conditions as
+well. However, it is not guaranteed, and in particular a WIM image captured with
+\fB@IMAGEX_PROGNAME@\fR on a POSIX-compliant system could contain such files. By
+default, invalid names will be ignored, and if there are multiple names
+differing only in case, one will be chosen to extract arbitrarily; however, with
+\fB--include-invalid-names\fR, all names will be sanitized and extracted in some
+form.