diff --git a/htdocs/svnwrite.html b/htdocs/svnwrite.html
index a1346be1..4873991a 100644
--- a/htdocs/svnwrite.html
+++ b/htdocs/svnwrite.html
@@ -25,6 +25,7 @@ maintainers and significant developers.</p>
   <li><a href="#checkin">Checking in a change</a></li>
   <li><a href="#example">Example check-in session</a></li>
   <li><a href="#branches">Creating and using branches</a></li>
+  <li><a href="#vendor">Private user and Vendor branches</a></li>
   <li><a href="#account">Tips&amp;Tricks around your account</a></li>
 </ol>
 
@@ -407,6 +408,72 @@ svn cp svn+ssh://<i>username</i>@gcc.gnu.org/svn/gcc/trunk \
 do not copy the entire set of ChangeLog entries.  Just use something
 like "Merge from mainline" or similar.</p>
 
+<hr />
+<h2 id="vendor">Private user and vendor branches"</h2>
+
+The GCC git repository is used by many people and the branch and tag
+namespace would become very polluted if all branches lived at the
+top-level naming space.  To help minimise the amount of data that
+needs to be fetched the git repository on gcc.gnu.org contains a
+number of private user and vendor branches that developers use to
+share their work.  These are not pulled by default, but simple
+configuration steps can give access to them.
+
+<ul>
+  <li>Private user branches live
+    in <code>refs/users/<i>username</i>/heads</code> with tags
+    in <code>refs/users/<i>username</i>/tags</code>.</li>
+  <li>Vendor branches live
+    in <code>refs/vendors/<i>vendor-name</i>/heads</code> with tags
+    in <code>refs/vendors/<i>vendor-name</i>/tags</code>.</li>
+</ul>
+
+To fetch any of these you will need to add a fetch refspec to your
+configuration.  For example, to fetch all the IBM vendor branches add to
+your default upstream pull
+
+<blockquote><pre>
+git config --add remote.origin.fetch "+refs/vendors/IBM/heads/*:refs/remotes/origin/IBM/*"
+git config --add remote.origin.fetch "+refs/vendors/IBM/tags/*:refs/tags/IBM/*"
+</pre></blockquote>
+
+this will cause <code>git pull</code> to fetch all the additional
+branches and make them available locally
+under <code>remotes/origin/IBM</code> and will also add any tags under
+the sub-namespace <code>IBM</code>.
+
+Setting up a tracking branch for one of the upstream vendor branches
+is slightly more complicated as <code>git branch
+--set-upstream-to</code> does not work properly.  However, it is
+possible to configure the branch information directly.  First, check
+out the branch you want to track, for example, to check out the
+<code>arm-9-branch</code> use something like:
+
+<blockquote><pre>
+git checkout -b ARM/arm-9-branch origin/ARM/arm-9-branch
+</pre></blockquote>
+
+then change the merge property for the branch to corectly identify the
+upstream source
+
+<blockquote><pre>
+git config branch.ARM/arm-9-branch.merge refs/vendors/ARM/heads/arm-9-branch
+</pre></blockquote>
+
+Pull operations will now correctly track the upstream branch.
+
+It is also possible to set up push operations so that local changes will be pushed to the private namespace.  For example, if you mirror your own private git information with
+
+<blockquote><pre>
+git config --add remote.origin.fetch "+refs/users/<i>my-userid</i>/heads/*:refs/remotes/origin/me/*"
+</pre></blockquote>
+
+then you can also add 
+<blockquote><pre>
+git config --add remote.origin.push "+refs/heads/me/*:refs/users/<i>my-userid</i>/heads/*"
+</pre></blockquote>
+and then any push from a branch that begins with <code>me/</code> will be pushed to the private area.
+
 <hr />
 <h2 id="account">Tips&amp;Tricks around your account</h2>