diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
index d535eec..3d5c5e2 100644
--- a/hostapd/hostapd.conf
+++ b/hostapd/hostapd.conf
@@ -909,11 +909,23 @@
 # The own IP address of the access point (used as NAS-IP-Address)
 own_ip_addr=127.0.0.1
 
-# Optional NAS-Identifier string for RADIUS messages. When used, this should be
-# a unique to the NAS within the scope of the RADIUS server. For example, a
-# fully qualified domain name can be used here.
+# NAS-Identifier string for RADIUS messages. When used, this should be unique
+# to the NAS within the scope of the RADIUS server. Please note that hostapd
+# uses a separate RADIUS client for each BSS and as such, a unique
+# nas_identifier value should be configured separately for each BSS. This is
+# particularly important for cases where RADIUS accounting is used
+# (Accounting-On/Off messages are interpreted as clearing all ongoing sessions
+# and that may get interpreted as applying to all BSSes if the same
+# NAS-Identifier value is used.) For example, a fully qualified domain name
+# prefixed with a unique identifier of the BSS (e.g., BSSID) can be used here.
+#
 # When using IEEE 802.11r, nas_identifier must be set and must be between 1 and
 # 48 octets long.
+#
+# It is mandatory to configure either own_ip_addr or nas_identifier to be
+# compliant with the RADIUS protocol. When using RADIUS accounting, it is
+# strongly recommended that nas_identifier is set to a unique value for each
+# BSS.
 #nas_identifier=ap.example.com
 
 # RADIUS client forced local IP address for the access point
@@ -1260,6 +1272,7 @@
 
 # PMK-R1 Key Holder identifier (dot11FTR1KeyHolderID)
 # 6-octet identifier as a hex string.
+# Defaults to BSSID.
 #r1_key_holder=000102030405
 
 # Reassociation deadline in time units (TUs / 1.024 ms; range 1000..65535)