diff --git a/configs/extconfig.conf.sample b/configs/extconfig.conf.sample
index 1d67fa5365..8630ac5711 100644
--- a/configs/extconfig.conf.sample
+++ b/configs/extconfig.conf.sample
@@ -53,13 +53,17 @@
 ; start at 1 and be sequential (i.e. if you have only priorities 1, 2,
 ; and 4, then 4 will be ignored, because there is no 3).
 ;
+;
+; Possible driver backends:
+;
 ; "odbc" is shown in the examples below, but is not the only valid realtime
-; engine.  There is:
+; engine.  Here are several of the possible options:
 ;    odbc ... res_config_odbc
 ;    sqlite ... res_config_sqlite
 ;    pgsql ... res_config_pgsql
 ;    curl ... res_config_curl
 ;    ldap ... res_config_ldap
+;    mysql ... res_config_mysql (available via add-ons in menuselect)
 ;
 ; Note: The res_config_pgsql and res_config_sqlite backends configure the
 ; database used in their respective configuration files and ignore the