diff --git a/README.txt b/README.txt
index 5e495fb..959b79b 100644
--- a/README.txt
+++ b/README.txt
@@ -45,6 +45,18 @@ For more detailed instructions on (1) and (2) above, please see the
 documentation online on drupal.org which includes links to external
 walk-throughs for various operating systems.
 
+You may safely clear any database cache tables once you have converted them to
+use memcache. You can clear Drupal core cache tables with the following MySQL
+queries:
+
+TRUNCATE TABLE cache;
+TRUNCATE TABLE cache_path;
+TRUNCATE TABLE cache_filter;
+TRUNCATE TABLE cache_bootstrap;
+TRUNCATE TABLE cache_page;
+
+Note that modules may create additional cache tables.
+
 ## Advanced Configuration ##
 
 This module is capable of working with one memcached instance or with multiple