diff --git a/common/sign.cpp b/common/sign.cpp
index 805f5bd..df9a7a9 100644
--- a/common/sign.cpp
+++ b/common/sign.cpp
@@ -77,6 +77,7 @@ AbstractProtocol::FieldFlags SignProtocol::fieldFlags(int index) const
     {
         case sign_magic:
         case sign_tlv_guid:
+        case sign_tlv_ttag:
         case sign_tlv_end:
             break;
 
@@ -116,6 +117,29 @@ QVariant SignProtocol::fieldData(int index, FieldAttrib attrib,
             }
             break;
         }
+        case sign_tlv_ttag:
+        {
+            switch(attrib)
+            {
+                case FieldName:
+                    return QString("T-Tag");
+                case FieldValue:
+                    return 0;
+                case FieldTextValue:
+                    return QString("%1").arg(0);
+                case FieldFrameValue:
+                {
+                    QByteArray fv;
+                    fv.resize(2);
+                    fv[0] = 0;
+                    fv[1] = kTypeLenTtagPlaceholder;
+                    return fv;
+                }
+                default:
+                    break;
+            }
+            break;
+        }
         case sign_tlv_guid:
         {
             quint32 guid = data.stream_guid() & 0xFFFFFF;
diff --git a/common/sign.h b/common/sign.h
index fa1809f..e7b8941 100644
--- a/common/sign.h
+++ b/common/sign.h
@@ -42,6 +42,8 @@ TLVs are encoded as
  Defined TLVs
  Type = 0, Len = 0 (0x00): End of TLVs
  Type = 1, Len = 3 (0x61): Stream GUID
+ Type = 2, Len = 1 (0x22): T-Tag Placeholder (0 value)
+ Type = 3, Len = 1 (0x23): T-Tag with actual value
 */
 
 class SignProtocol : public AbstractProtocol
@@ -52,6 +54,7 @@ public:
         // Frame Fields
         sign_tlv_end = 0,
         sign_tlv_guid,
+        sign_tlv_ttag,
         sign_magic,
 
         // Meta Fields
@@ -88,6 +91,8 @@ private:
     static const quint32 kSignMagic = 0x1d10c0da; // coda! (unicode - 0x1d10c)
     static const quint8 kTypeLenEnd = 0x00;
     static const quint8 kTypeLenGuid = 0x61;
+    static const quint8 kTypeLenTtagPlaceholder = 0x22;
+    static const quint8 kTypeLenTtag = 0x23;
     OstProto::Sign data;
 };