--- a/NEWS
+++ b/NEWS
@@ -25,6 +25,9 @@
     generic sense) arithmetic routines.  (thanks to Thiemo Seufer)
   * optimization: direct conversion of (unsigned-byte 32) to floats on
     the PowerPC platform.
+  * optimization: structure instances with raw slots now use less
+    memory, and probably show better memory locality.  (thanks to
+    David Lichteblau)
   * contrib improvement: it's harder to cause SOCKET-CLOSE to close()
     the wrong file descriptor; implementation of SOCKET-OPEN-P.
     (thanks to Tony Martinez)