#define ARPOP_REVREPLY 4 /* response giving protocol address */
#define ARPOP_INVREQUEST 8 /* request to identify peer */
#define ARPOP_INVREPLY 9 /* response identifying peer */
-#define ARPOP_NAK 10 /* NAK - only valif for ATM ARP */
+#define ARPOP_NAK 10 /* NAK - only valid for ATM ARP */
/*
* The remaining fields are variable in size,