diff --git a/doc/man/man5/slapd-config.5 b/doc/man/man5/slapd-config.5
index 0ed18755eaa1ecc679d9a666c37736bd6a7895be..e8846b2f823b2360254f8b75638ebb4387aec12d 100644
--- a/doc/man/man5/slapd-config.5
+++ b/doc/man/man5/slapd-config.5
@@ -747,15 +747,16 @@ size allowed.  0 disables security layers.  The default is 65536.
 Specify an integer ID from 0 to 4095 for this server (limited
 to 3 hexadecimal digits).  The ID may also be specified as a
 hexadecimal ID by prefixing the value with "0x".
-These IDs are
+Non-zero IDs are
 required when using multimaster replication and each master must have a
-unique ID. Note that this requirement also applies to separate masters
+unique non-zero ID. Note that this requirement also applies to separate masters
 contributing to a glued set of databases.
 If the URL is provided, this directive may be specified
 multiple times, providing a complete list of participating servers
 and their IDs. The fully qualified hostname of each server should be
 used in the supplied URLs. The IDs are used in the "replica id" field
-of all CSNs generated by the specified server. The default value is zero.
+of all CSNs generated by the specified server. The default value is zero, which
+is only valid for single master replication.
 Example:
 .LP
 .nf
diff --git a/doc/man/man5/slapd.conf.5 b/doc/man/man5/slapd.conf.5
index e85afc7b158fb1acf61892f2c3d0f5233f5e5db4..8a038c0c6bd591906330b044dc3af70a060fa858 100644
--- a/doc/man/man5/slapd.conf.5
+++ b/doc/man/man5/slapd.conf.5
@@ -937,15 +937,16 @@ e.g. ldapi:// (and eventually IPSEC).  It is not normally used.
 Specify an integer ID from 0 to 4095 for this server (limited
 to 3 hexadecimal digits).  The ID may also be specified as a
 hexadecimal ID by prefixing the value with "0x".
-These IDs are
+Non-zero IDs are
 required when using multimaster replication and each master must have a
-unique ID. Note that this requirement also applies to separate masters
+unique non-zero ID. Note that this requirement also applies to separate masters
 contributing to a glued set of databases.
 If the URL is provided, this directive may be specified
 multiple times, providing a complete list of participating servers
 and their IDs. The fully qualified hostname of each server should be
 used in the supplied URLs. The IDs are used in the "replica id" field
-of all CSNs generated by the specified server. The default value is zero.
+of all CSNs generated by the specified server. The default value is zero, which
+is only valid for single master replication.
 Example:
 .LP
 .nf