diff --git a/dns.go b/dns.go
index 0086866f..8deaf0a1 100644
--- a/dns.go
+++ b/dns.go
@@ -124,7 +124,7 @@ type Exchange struct {
 // There are many types of messages,
 // but they all share the same header.
 type RR_Header struct {
-	Name     string "cdomain-name"
+	Name     string `dns:"cdomain-name"`
 	Rrtype   uint16
 	Class    uint16
 	Ttl      uint32
diff --git a/dnssec.go b/dnssec.go
index 6c3612c0..360eeb49 100644
--- a/dnssec.go
+++ b/dnssec.go
@@ -81,7 +81,7 @@ type rrsigWireFmt struct {
 	Expiration  uint32
 	Inception   uint32
 	KeyTag      uint16
-	SignerName  string "domain-name"
+	SignerName  string `dns:"domain-name"`
 	/* No Signature */
 }
 
@@ -90,7 +90,7 @@ type dnskeyWireFmt struct {
 	Flags     uint16
 	Protocol  uint8
 	Algorithm uint8
-	PublicKey string "base64"
+	PublicKey string `dns:"base64"`
 	/* Nothing is left out */
 }
 
diff --git a/edns.go b/edns.go
index 0ab762b8..4191057f 100644
--- a/edns.go
+++ b/edns.go
@@ -17,7 +17,7 @@ const (
 // An ENDS0 option rdata element.
 type Option struct {
 	Code uint16
-	Data string "hex"
+	Data string `dns:"hex"`
 }
 
 /* 
@@ -34,7 +34,7 @@ type Option struct {
 
 type RR_OPT struct {
 	Hdr    RR_Header
-	Option []Option "opt" // tag is used in Pack and Unpack
+	Option []Option `dns:"opt"` // tag is used in Pack and Unpack
 }
 
 func (rr *RR_OPT) Header() *RR_Header {
@@ -126,6 +126,7 @@ func (rr *RR_OPT) Nsid() string {
 			return "NSID: " + rr.Option[i].Data
 		}
 	}
+	// TODO: error or nil string?
 	return "Not found"
 }
 
diff --git a/msg.go b/msg.go
index 2da1b391..219db803 100644
--- a/msg.go
+++ b/msg.go
@@ -371,9 +371,9 @@ func packStructValue(val reflect.Value, msg []byte, off int, compression map[str
 		default:
 			return lenmsg, false
 		case reflect.Slice:
-			switch val.Type().Field(i).Tag {
+			switch val.Type().Field(i).Tag.Get("dns") {
 			default:
-				println("dns: unknown tag packing slice", val.Type().Field(i).Tag)
+				println("dns: unknown tag packing slice", val.Type().Field(i).Tag.Get("dns"), '"', val.Type().Field(i).Tag , '"')
 				return lenmsg, false
 			case "domain-name":
 				for j := 0; j < val.Field(i).Len(); j++ {
@@ -550,7 +550,7 @@ func packStructValue(val reflect.Value, msg []byte, off int, compression map[str
 			// There are multiple string encodings.
 			// The tag distinguishes ordinary strings from domain names.
 			s := fv.String()
-			switch val.Type().Field(i).Tag {
+			switch val.Type().Field(i).Tag.Get("dns") {
 			default:
 				return lenmsg, false
 			case "base64":
@@ -562,14 +562,12 @@ func packStructValue(val reflect.Value, msg []byte, off int, compression map[str
 				copy(msg[off:off+len(b64)], b64)
 				off += len(b64)
 			case "domain-name":
-				fallthrough // No compression
-			case "cdomain-name":
-				if val.Type().Field(i).Tag == "cdomain-name" {
-					off, ok = PackDomainName(s, msg, off, compression, true && compress)
-				} else {
-					off, ok = PackDomainName(s, msg, off, compression, false && compress)
+				if off, ok = PackDomainName(s, msg, off, compression, false && compress); !ok {
+					println("dns: overflow packing domain-name", off)
+					return lenmsg, false
 				}
-				if !ok {
+			case "cdomain-name":
+				if off, ok = PackDomainName(s, msg, off, compression, true && compress); !ok {
 					println("dns: overflow packing domain-name", off)
 					return lenmsg, false
 				}
@@ -653,7 +651,7 @@ func unpackStructValue(val reflect.Value, msg []byte, off int) (off1 int, ok boo
 			println("dns: unknown case unpacking struct")
 			return lenmsg, false
 		case reflect.Slice:
-			switch val.Type().Field(i).Tag {
+			switch val.Type().Field(i).Tag.Get("dns") {
 			default:
 				println("dns: unknown tag unpacking slice", val.Type().Field(i).Tag)
 				return lenmsg, false
@@ -820,7 +818,7 @@ func unpackStructValue(val reflect.Value, msg []byte, off int) (off1 int, ok boo
 			off += 6
 		case reflect.String:
 			var s string
-			switch val.Type().Field(i).Tag {
+			switch val.Type().Field(i).Tag.Get("dns") {
 			default:
 				println("dns: unknown tag unpacking string")
 				return lenmsg, false
@@ -832,7 +830,7 @@ func unpackStructValue(val reflect.Value, msg []byte, off int) (off1 int, ok boo
 					println("dns: overflow when unpacking hex string")
 					return lenmsg, false
 				}
-				s = hex.EncodeToString(msg[off : endrr])
+				s = hex.EncodeToString(msg[off:endrr])
 				off = endrr
 			case "base64":
 				// Rest of the RR is base64 encoded value
@@ -842,7 +840,7 @@ func unpackStructValue(val reflect.Value, msg []byte, off int) (off1 int, ok boo
 					println("dns: failure unpacking base64")
 					return lenmsg, false
 				}
-				s = unpackBase64(msg[off : endrr])
+				s = unpackBase64(msg[off:endrr])
 				off = endrr
 			case "cdomain-name":
 				fallthrough
diff --git a/nsecx.go b/nsecx.go
index f486d7e7..684fb86b 100644
--- a/nsecx.go
+++ b/nsecx.go
@@ -14,7 +14,7 @@ const (
 )
 
 type saltWireFmt struct {
-	Salt string "size-hex"
+	Salt string `dns:"size-hex"`
 }
 
 // HashName hashes a string (label) according to RFC5155. It returns the hashed string.
diff --git a/tsig.go b/tsig.go
index db09b2ec..8bac6d21 100644
--- a/tsig.go
+++ b/tsig.go
@@ -72,15 +72,15 @@ const (
 // RFC 2845.
 type RR_TSIG struct {
 	Hdr        RR_Header
-	Algorithm  string "domain-name"
+	Algorithm  string `dns:"domain-name"`
 	TimeSigned uint64
 	Fudge      uint16
 	MACSize    uint16
-	MAC        string "size-hex"
+	MAC        string `dns:"size-hex"`
 	OrigId     uint16
 	Error      uint16
 	OtherLen   uint16
-	OtherData  string "size-hex"
+	OtherData  string `dns:"size-hex"`
 }
 
 func (rr *RR_TSIG) Header() *RR_Header {
@@ -112,24 +112,24 @@ func (rr *RR_TSIG) Len() int {
 // RFC 2845, section 3.4.2. TSIG Variables.
 type tsigWireFmt struct {
 	// From RR_Header
-	Name  string "domain-name"
+	Name  string `dns:"domain-name"`
 	Class uint16
 	Ttl   uint32
 	// Rdata of the TSIG
-	Algorithm  string "domain-name"
+	Algorithm  string `dns:"domain-name"`
 	TimeSigned uint64
 	Fudge      uint16
 	// MACSize, MAC and OrigId excluded
 	Error     uint16
 	OtherLen  uint16
-	OtherData string "size-hex"
+	OtherData string `dns:"size-hex"`
 }
 
 // If we have the MAC use this type to convert it to wiredata.
 // Section 3.4.3. Request MAC
 type macWireFmt struct {
 	MACSize uint16
-	MAC     string "size-hex"
+	MAC     string `dns:"size-hex"`
 }
 
 // 3.3. Time values used in TSIG calculations
diff --git a/types.go b/types.go
index ced0c9f1..edea7f75 100644
--- a/types.go
+++ b/types.go
@@ -129,7 +129,7 @@ const (
 
 // DNS queries.
 type Question struct {
-	Name   string "cdomain-name" // "cdomain-name" specifies encoding (and may be compressed)
+	Name   string `dns:"cdomain-name"` // "cdomain-name" specifies encoding (and may be compressed)
 	Qtype  uint16
 	Qclass uint16
 }
@@ -179,7 +179,7 @@ func (rr *RR_ANY) Len() int {
 
 type RR_CNAME struct {
 	Hdr    RR_Header
-	Target string "cdomain-name"
+	Target string `dns:"cdomain-name"`
 }
 
 func (rr *RR_CNAME) Header() *RR_Header {
@@ -215,7 +215,7 @@ func (rr *RR_HINFO) Len() int {
 
 type RR_MB struct {
 	Hdr RR_Header
-	Mb  string "cdomain-name"
+	Mb  string `dns:"cdomain-name"`
 }
 
 func (rr *RR_MB) Header() *RR_Header {
@@ -233,7 +233,7 @@ func (rr *RR_MB) Len() int {
 
 type RR_MG struct {
 	Hdr RR_Header
-	Mg  string "cdomain-name"
+	Mg  string `dns:"cdomain-name"`
 }
 
 func (rr *RR_MG) Header() *RR_Header {
@@ -251,8 +251,8 @@ func (rr *RR_MG) Len() int {
 
 type RR_MINFO struct {
 	Hdr   RR_Header
-	Rmail string "cdomain-name"
-	Email string "cdomain-name"
+	Rmail string `dns:"cdomain-name"`
+	Email string `dns:"cdomain-name"`
 }
 
 func (rr *RR_MINFO) Header() *RR_Header {
@@ -271,7 +271,7 @@ func (rr *RR_MINFO) Len() int {
 
 type RR_MR struct {
 	Hdr RR_Header
-	Mr  string "cdomain-name"
+	Mr  string `dns:"cdomain-name"`
 }
 
 func (rr *RR_MR) Header() *RR_Header {
@@ -290,7 +290,7 @@ func (rr *RR_MR) Len() int {
 type RR_MX struct {
 	Hdr  RR_Header
 	Pref uint16
-	Mx   string "cdomain-name"
+	Mx   string `dns:"cdomain-name"`
 }
 
 func (rr *RR_MX) Header() *RR_Header {
@@ -308,7 +308,7 @@ func (rr *RR_MX) Len() int {
 
 type RR_NS struct {
 	Hdr RR_Header
-	Ns  string "cdomain-name"
+	Ns  string `dns:"cdomain-name"`
 }
 
 func (rr *RR_NS) Header() *RR_Header {
@@ -326,7 +326,7 @@ func (rr *RR_NS) Len() int {
 
 type RR_PTR struct {
 	Hdr RR_Header
-	Ptr string "cdomain-name"
+	Ptr string `dns:"cdomain-name"`
 }
 
 func (rr *RR_PTR) Header() *RR_Header {
@@ -344,8 +344,8 @@ func (rr *RR_PTR) Len() int {
 
 type RR_SOA struct {
 	Hdr     RR_Header
-	Ns      string "cdomain-name"
-	Mbox    string "cdomain-name"
+	Ns      string `dns:"cdomain-name"`
+	Mbox    string `dns:"cdomain-name"`
 	Serial  uint32
 	Refresh uint32
 	Retry   uint32
@@ -374,7 +374,7 @@ func (rr *RR_SOA) Len() int {
 
 type RR_TXT struct {
 	Hdr RR_Header
-	Txt []string "txt"
+	Txt []string `dns:"txt"`
 }
 
 func (rr *RR_TXT) Header() *RR_Header {
@@ -403,7 +403,7 @@ func (rr *RR_TXT) Len() int {
 
 type RR_SPF struct {
 	Hdr RR_Header
-	Txt []string "txt"
+	Txt []string `dns:"txt"`
 }
 
 func (rr *RR_SPF) Header() *RR_Header {
@@ -435,7 +435,7 @@ type RR_SRV struct {
 	Priority uint16
 	Weight   uint16
 	Port     uint16
-	Target   string "domain-name"
+	Target   string `dns:"domain-name"`
 }
 
 func (rr *RR_SRV) Header() *RR_Header {
@@ -461,7 +461,7 @@ type RR_NAPTR struct {
 	Flags       string
 	Service     string
 	Regexp      string
-	Replacement string "domain-name"
+	Replacement string `dns:"domain-name"`
 }
 
 func (rr *RR_NAPTR) Header() *RR_Header {
@@ -489,7 +489,7 @@ type RR_CERT struct {
 	Type        uint16
 	KeyTag      uint16
 	Algorithm   uint8
-	Certificate string "base64"
+	Certificate string `dns:"base64"`
 }
 
 func (rr *RR_CERT) Header() *RR_Header {
@@ -511,7 +511,7 @@ func (rr *RR_CERT) Len() int {
 // See RFC 2672.
 type RR_DNAME struct {
 	Hdr    RR_Header
-	Target string "domain-name"
+	Target string `dns:"domain-name"`
 }
 
 func (rr *RR_DNAME) Header() *RR_Header {
@@ -529,7 +529,7 @@ func (rr *RR_DNAME) Len() int {
 
 type RR_A struct {
 	Hdr RR_Header
-	A   net.IP "a"
+	A   net.IP `dns:"a"`
 }
 
 func (rr *RR_A) Header() *RR_Header {
@@ -546,7 +546,7 @@ func (rr *RR_A) Len() int {
 
 type RR_AAAA struct {
 	Hdr  RR_Header
-	AAAA net.IP "aaaa"
+	AAAA net.IP `dns:"aaaa"`
 }
 
 func (rr *RR_AAAA) Header() *RR_Header {
@@ -593,8 +593,8 @@ type RR_RRSIG struct {
 	Expiration  uint32
 	Inception   uint32
 	KeyTag      uint16
-	SignerName  string "domain-name"
-	Signature   string "base64"
+	SignerName  string `dns:"domain-name"`
+	Signature   string `dns:"base64"`
 }
 
 func (rr *RR_RRSIG) Header() *RR_Header {
@@ -620,8 +620,8 @@ func (rr *RR_RRSIG) Len() int {
 
 type RR_NSEC struct {
 	Hdr        RR_Header
-	NextDomain string   "domain-name"
-	TypeBitMap []uint16 "nsec"
+	NextDomain string   `dns:"domain-name"`
+	TypeBitMap []uint16 `dns:"nsec"`
 }
 
 func (rr *RR_NSEC) Header() *RR_Header {
@@ -651,7 +651,7 @@ type RR_DS struct {
 	KeyTag     uint16
 	Algorithm  uint8
 	DigestType uint8
-	Digest     string "hex"
+	Digest     string `dns:"hex"`
 }
 
 func (rr *RR_DS) Header() *RR_Header {
@@ -674,7 +674,7 @@ type RR_DLV struct {
 	KeyTag     uint16
 	Algorithm  uint8
 	DigestType uint8
-	Digest     string "hex"
+	Digest     string `dns:"hex"`
 }
 
 func (rr *RR_DLV) Header() *RR_Header {
@@ -695,7 +695,7 @@ func (rr *RR_DLV) Len() int {
 type RR_KX struct {
 	Hdr        RR_Header
 	Preference uint16
-	Exchanger  string "domain-name"
+	Exchanger  string `dns:"domain-name"`
 }
 
 func (rr *RR_KX) Header() *RR_Header {
@@ -716,7 +716,7 @@ type RR_TA struct {
 	KeyTag     uint16
 	Algorithm  uint8
 	DigestType uint8
-	Digest     string "hex"
+	Digest     string `dns:"hex"`
 }
 
 func (rr *RR_TA) Header() *RR_Header {
@@ -736,8 +736,8 @@ func (rr *RR_TA) Len() int {
 
 type RR_TALINK struct {
 	Hdr          RR_Header
-	PreviousName string "domain"
-	NextName     string "domain"
+	PreviousName string `dns:"domain"`
+	NextName     string `dns:"domain"`
 }
 
 func (rr *RR_TALINK) Header() *RR_Header {
@@ -757,7 +757,7 @@ type RR_SSHFP struct {
 	Hdr         RR_Header
 	Algorithm   uint8
 	Type        uint8
-	FingerPrint string "hex"
+	FingerPrint string `dns:"hex"`
 }
 
 func (rr *RR_SSHFP) Header() *RR_Header {
@@ -779,8 +779,8 @@ type RR_IPSECKEY struct {
 	Precedence  uint8
 	GatewayType uint8
 	Algorithm   uint8
-	Gateway     string "ipseckey"
-	PublicKey   string "base64"
+	Gateway     string `dns:"ipseckey"`
+	PublicKey   string `dns:"base64"`
 }
 
 func (rr *RR_IPSECKEY) Header() *RR_Header {
@@ -805,7 +805,7 @@ type RR_DNSKEY struct {
 	Flags     uint16
 	Protocol  uint8
 	Algorithm uint8
-	PublicKey string "base64"
+	PublicKey string `dns:"base64"`
 }
 
 func (rr *RR_DNSKEY) Header() *RR_Header {
@@ -830,10 +830,10 @@ type RR_NSEC3 struct {
 	Flags      uint8
 	Iterations uint16
 	SaltLength uint8
-	Salt       string "size-hex"
+	Salt       string `dns:"size-hex"`
 	HashLength uint8
-	NextDomain string   "size-base32"
-	TypeBitMap []uint16 "nsec"
+	NextDomain string   `dns:"size-base32"`
+	TypeBitMap []uint16 `dns:"nsec"`
 }
 
 func (rr *RR_NSEC3) Header() *RR_Header {
@@ -868,7 +868,7 @@ type RR_NSEC3PARAM struct {
 	Flags      uint8
 	Iterations uint16
 	SaltLength uint8
-	Salt       string "hex" // hexsize??
+	Salt       string `dns:"hex"` // hexsize??
 }
 
 func (rr *RR_NSEC3PARAM) Header() *RR_Header {
@@ -890,7 +890,7 @@ func (rr *RR_NSEC3PARAM) Len() int {
 
 type RR_TKEY struct {
 	Hdr        RR_Header
-	Algorithm  string "domain-name"
+	Algorithm  string `dns:"domain-name"`
 	Inception  uint32
 	Expiration uint32
 	Mode       uint16
@@ -918,7 +918,7 @@ func (rr *RR_TKEY) Len() int {
 // Unknown RR representation
 type RR_RFC3597 struct {
 	Hdr   RR_Header
-	Rdata string "hex"
+	Rdata string `dns:"hex"`
 }
 
 func (rr *RR_RFC3597) Header() *RR_Header {
@@ -939,7 +939,7 @@ type RR_URI struct {
 	Hdr      RR_Header
 	Priority uint16
 	Weight   uint16
-	Target   string "txt"
+	Target   string `dns:"txt"`
 }
 
 func (rr *RR_URI) Header() *RR_Header {
@@ -958,7 +958,7 @@ func (rr *RR_URI) Len() int {
 
 type RR_DHCID struct {
 	Hdr    RR_Header
-	Digest string "base64"
+	Digest string `dns:"base64"`
 }
 
 func (rr *RR_DHCID) Header() *RR_Header {
@@ -979,7 +979,7 @@ type RR_TLSA struct {
 	Usage        uint8
 	Selector     uint8
 	MatchingType uint8
-	Certificate  string "hex"
+	Certificate  string `dns:"hex"`
 }
 
 func (rr *RR_TLSA) Header() *RR_Header {
@@ -1003,9 +1003,9 @@ type RR_HIP struct {
 	HitLength          uint8
 	PublicKeyAlgorithm uint8
 	PublicKeyLength    uint16
-	Hit                string   "hex"
-	PublicKey          string   "base64"
-	RendezvousServers  []string "domain-name"
+	Hit                string   `dns:"hex"`
+	PublicKey          string   `dns:"base64"`
+	RendezvousServers  []string `dns:"domain-name"`
 }
 
 func (rr *RR_HIP) Header() *RR_Header {