--- a/CHANGES.html	Tue Jun 15 11:27:51 2010 -0700
+++ b/CHANGES.html	Wed Jun 16 10:55:13 2010 +0100
@@ -69,6 +69,28 @@
 
 <h2>Changes to existing API:</h2>
 
+<ul>
+<li><b>Changes to construction and naming of Wi-Fi transmit rates:</b>
+A reorganisation of the construction of Wi-Fi transmit rates has been
+undertaken with the aim of simplifying the task of supporting further
+IEEE 802.11 PHYs. This work has been completed under the auspices of
+Bug 871.
+
+From the viewpoint of simulation scripts not part of the ns-3
+distribution, the key change is that WifiMode names of the form
+wifi<em>x</em>-<em>n</em>mbs are now invalid. Names now take the
+form <em>Cccc</em>Rate<em>n</em>Mbps[BW<em>b</em>MHz],
+where <em>n</em> is the root bitrate in megabits-per-second as before
+(with only significant figures included, and an underscore replacing
+any decimal point), and <em>Cccc</em> is a representation of the
+Modulation Class as defined in Table 9-2 of IEEE
+Std. 802.11-2007. Currently-supported options for <em>Cccc</em>
+are <em>Ofdm</em> and <em>Dsss</em>. For modulation classes where
+optional reduced-bandwidth transmission is possible, this is captured
+in the final part of the form above, with <em>b</em> specifying the
+nominal signal bandwidth in megahertz.
+</ul>
+
 <h2>Changed behavior:</h2>
 <ul>
 <li><b>Queue trace behavior during Enqueue changed:</b> The behavior of the