diff --git a/UPGRADE b/UPGRADE
index d9ac8bb8..e9fd2d9a 100644
--- a/UPGRADE
+++ b/UPGRADE
@@ -252,6 +252,9 @@ OTHER CHANGES:
 	"Admin Report Log Viewer" linked from the "Admin Utilities" page which 
 	allows you to see the reports that have been run on the system.
 
+43. Added option to the AST_DB_dead_cb_purge.pl script to remove duplicate 
+	callback entries for a single lead, keeping the newest one only.
+
 
 
 
diff --git a/docs/BASE_INSTALL.txt b/docs/BASE_INSTALL.txt
index e5da40fc..664c3436 100644
--- a/docs/BASE_INSTALL.txt
+++ b/docs/BASE_INSTALL.txt
@@ -452,7 +452,9 @@ PHASE 6: ADDING CRONTAB ENTRIES FOR ASTGUICLIENT/VICIDIAL SCRIPTS
 #*/5 * * * * /usr/share/astguiclient/AST_cleanup_agent_log.pl --only-qm-live-call-check
 
 # cleanup of the scheduled callback records
-25 0 * * * /usr/share/astguiclient/AST_DB_dead_cb_purge.pl --purge-non-cb -q
+25 0 * * * /usr/share/astguiclient/AST_DB_dead_cb_purge.pl --purge-non-cb --quiet
+# removal of duplicate scheduled callback records
+#35 0 * * * /usr/share/astguiclient/AST_DB_dead_cb_purge.pl --purge-non-cb --remove-dup-cb --quiet
 
 ## uncomment below if using Vtiger
 #1 1 * * * /usr/share/astguiclient/Vtiger_optimize_all_tables.pl --quiet
diff --git a/docs/SCRATCH_INSTALL.txt b/docs/SCRATCH_INSTALL.txt
index 93081e42..fe2e5676 100644
--- a/docs/SCRATCH_INSTALL.txt
+++ b/docs/SCRATCH_INSTALL.txt
@@ -2448,7 +2448,9 @@ SUBPHASE 6.5: setting up astguiclient scripts for continuous running
 #*/5 * * * * /usr/share/astguiclient/AST_cleanup_agent_log.pl --only-qm-live-call-check
 
 # cleanup of the scheduled callback records
-25 0 * * * /usr/share/astguiclient/AST_DB_dead_cb_purge.pl --purge-non-cb -q
+25 0 * * * /usr/share/astguiclient/AST_DB_dead_cb_purge.pl --purge-non-cb --quiet
+# removal of duplicate scheduled callback records
+#35 0 * * * /usr/share/astguiclient/AST_DB_dead_cb_purge.pl --purge-non-cb --remove-dup-cb --quiet
 
 ## uncomment below if using Vtiger
 #1 1 * * * /usr/share/astguiclient/Vtiger_optimize_all_tables.pl --quiet