diff --git a/doc/arm/Bv9ARM-book.xml b/doc/arm/Bv9ARM-book.xml
index 37618d9205..eb56c97152 100644
--- a/doc/arm/Bv9ARM-book.xml
+++ b/doc/arm/Bv9ARM-book.xml
@@ -10796,7 +10796,7 @@ example.com CNAME rpz-tcp-only.
tcp-only yes_or_no ;
transfers number ;
transfer-format ( one-answer | many-answers ) ; ]
- keys { string ; string ; ... } ;
+ keys { key_id };
transfer-source (ip4_addr | *) port ip_port dscp ip_dscp ;
transfer-source-v6 (ip6_addr | *) port ip_port dscp ip_dscp ;
notify-source (ip4_addr | *) port ip_port dscp ip_dscp ;
@@ -11007,11 +11007,7 @@ example.com CNAME rpz-tcp-only.
- Although the grammar of the keys
- clause
- allows for multiple keys, only a single key per server is
- currently
- supported.
+ Only a single key per server is currently supported.