diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
index 390c753..1c1e43d 100644
--- a/hostapd/hostapd.conf
+++ b/hostapd/hostapd.conf
@@ -127,7 +127,9 @@
 
 # Operation mode (a = IEEE 802.11a, b = IEEE 802.11b, g = IEEE 802.11g,
 # ad = IEEE 802.11ad (60 GHz); a/g options are used with IEEE 802.11n, too, to
-# specify band)
+# specify band). When using ACS (see channel parameter), a special value "any"
+# can be used to indicate that any support band can be used. This special case
+# is currently supported only with drivers with which offloaded ACS is used.
 # Default: IEEE 802.11b
 hw_mode=g