* NULL, a default string is used. Please see the manual page for
* <b>imagex capture</b> for more information.
* @param config_len
- * Length of the string @a config in bytes. Ignored if @a config is @c
- * NULL.
+ * Length of the string @a config in bytes, not including an optional
+ * null-terminator. Ignored if @a config is @c NULL.
* @param add_image_flags
* Bitwise OR of flags prefixed with WIMLIB_ADD_IMAGE_FLAG.
* @param progress_func