diff --git a/examples/udhcp/udhcpd.conf b/examples/udhcp/udhcpd.conf
index df1258aaf..6eb10852e 100644
--- a/examples/udhcp/udhcpd.conf
+++ b/examples/udhcp/udhcpd.conf
@@ -79,7 +79,7 @@ option	staticroutes	10.0.0.0/8 10.127.0.1, 10.11.12.0/24 10.11.12.1
 option	0x08	01020304	# option 8: "cookie server IP addr: 1.2.3.4"
 option	14	"dumpfile"
 
-# Currently supported options [hex option value] (for more info, see options.c):
+# Currently supported options [hex option value] (for more info, see common.c):
 #opt lease      NUM             # [0x33]
 #opt subnet     IP              # [0x01]
 #opt broadcast  IP              # [0x1c]
@@ -91,17 +91,20 @@ option	14	"dumpfile"
 #opt search     STRING_LIST     # [0x77] search domains
 #opt nisdomain  STRING          # [0x28]
 #opt timezone   NUM             # [0x02] (localtime - UTC_time) in seconds. signed
+#opt tzstr      STRING          # [0x64] RFC 4833. IEEE 1003.1 TZ string
+#opt tzdbstr    STRING          # [0x65] RFC 4833. Reference to the TZ database string
 #opt tftp       STRING          # [0x42] tftp server name
 #opt bootfile   STRING          # [0x43] tftp file to download (e.g. kernel image)
 #opt bootsize   NUM             # [0x0d] size of that file
 #opt rootpath   STRING          # [0x11] (NFS) path to mount as root fs
 #opt wpad       STRING          # [0xfc] Web Proxy Auto Discovery Protocol
 #opt serverid   IP              # [0x36] default: server's IP
-#opt message    STRING          # [0x38] error message (udhcpd sends it on success too)
+#opt message    STRING          # [0x38] error message (if set, udhcpd would send it on success too)
 #opt vlanid     NUM             # [0x84] 802.1P VLAN ID
 #opt vlanpriority NUM           # [0x85] 802.1Q VLAN priority
+#opt vendor     STRING          # [0x3c] client's vendor string, not intended to be sent by DHCP servers
 # RFC 5071: PXELINUX Options
-#opt 0xd0       F100747E        # [0xd0] magic
+#opt 0xd0       F100747E        # [0xd0] magic needed for other options to be recognized by clients
 #opt pxeconffile STRING         # [0xd1]
 #opt pxepathprefix STRING       # [0xd2]
 #opt reboottime NUM             # [0xd3] bootstrap timeout