ReleaseNotes in sup-0.9.1 vs ReleaseNotes in sup-0.10

@@ -1,4 +1,14 @@
+Release 0.10:
+
+The Xapian backend is now the default. Convert your old, crash-prone Ferret
+index to Xapian by running sup-convert-ferret-index.
+
+Using a Ferret backend will produce a deprecation notice, and will not be
+supported in 0.11.
+
+Many thanks to Rich Lane.
+
 Release 0.9.1:
 
 This is mainly a bugfix release, with a couple minor new features rolled up.
 
 If you are using the Ferret backend, consider convering soon. I will probably