diff --git a/pvDataApp/factory/Compare.cpp b/pvDataApp/factory/Compare.cpp
index 12a80f9..b62f3c9 100644
--- a/pvDataApp/factory/Compare.cpp
+++ b/pvDataApp/factory/Compare.cpp
@@ -70,6 +70,8 @@ bool operator==(const Structure& a, const Structure& b)
 {
     if(&a==&b)
         return true;
+    if (a.getID()!=b.getID())
+    	return false;
     size_t nflds=a.getNumberFields();
     if (b.getNumberFields()!=nflds)
         return false;
diff --git a/pvDataApp/factory/FieldCreateFactory.cpp b/pvDataApp/factory/FieldCreateFactory.cpp
index 54e4c99..9ac6453 100644
--- a/pvDataApp/factory/FieldCreateFactory.cpp
+++ b/pvDataApp/factory/FieldCreateFactory.cpp
@@ -71,6 +71,25 @@ void Scalar::toString(StringBuilder buffer,int indentLevel) const{
     ScalarTypeFunc::toString(buffer,scalarType);
 }
 
+static const String idScalarLUT[] = {
+	"boolean", // pvBoolean
+	"byte",    // pvByte
+	"short",   // pvShort
+	"int",     // pvInt
+	"long",    // pvLong
+	"ubyte",   // pvUByte
+	"ushort",  // pvUShort
+	"uint",    // pvUInt
+	"ulong",   // pvULong
+	"float",   // pvFloat
+	"double",  // pvDouble
+	"string"   // pvString
+};
+
+String Scalar::getID() const
+{
+    return idScalarLUT[scalarType];
+}
 
 static const int8 typeCodeLUT[] = {
     0x00, // pvBoolean
@@ -99,6 +118,7 @@ void Scalar::deserialize(ByteBuffer *buffer, DeserializableControl *control) {
 
 static void serializeStructureField(const Structure* structure, ByteBuffer* buffer, SerializableControl* control)
 {
+    SerializeHelper::serializeString(structure->getID(), buffer, control);
     FieldConstPtrArray const & fields = structure->getFields();
     StringArray const & fieldNames = structure->getFieldNames();
     std::size_t len = fields.size();
@@ -112,6 +132,7 @@ static void serializeStructureField(const Structure* structure, ByteBuffer* buff
 
 static StructureConstPtr deserializeStructureField(const FieldCreate* fieldCreate, ByteBuffer* buffer, DeserializableControl* control)
 {
+    String id = SerializeHelper::deserializeString(buffer, control);
     const std::size_t size = SerializeHelper::readSize(buffer, control);
     FieldConstPtrArray fields; fields.reserve(size);
     StringArray fieldNames; fieldNames.reserve(size);
@@ -121,7 +142,7 @@ static StructureConstPtr deserializeStructureField(const FieldCreate* fieldCreat
         fields.push_back(control->cachedDeserialize(buffer));
     }
 
-    return fieldCreate->createStructure(fieldNames, fields);
+    return fieldCreate->createStructure(id, fieldNames, fields);
 }
 
 ScalarArray::ScalarArray(ScalarType elementType)
@@ -129,6 +150,26 @@ ScalarArray::ScalarArray(ScalarType elementType)
 
 ScalarArray::~ScalarArray() {}
 
+static const String idScalarArrayLUT[] = {
+	"boolean[]", // pvBoolean
+	"byte[]",    // pvByte
+	"short[]",   // pvShort
+	"int[]",     // pvInt
+	"long[]",    // pvLong
+	"ubyte[]",   // pvUByte
+	"ushort[]",  // pvUShort
+	"uint[]",    // pvUInt
+	"ulong[]",   // pvULong
+	"float[]",   // pvFloat
+	"double[]",  // pvDouble
+	"string[]"   // pvString
+};
+
+String ScalarArray::getID() const
+{
+    return idScalarArrayLUT[elementType];
+}
+
 void ScalarArray::toString(StringBuilder buffer,int indentLevel) const{
     ScalarTypeFunc::toString(buffer,elementType);
     *buffer += "[]";
@@ -152,6 +193,12 @@ StructureArray::~StructureArray() {
     if(debugLevel==highDebug) printf("~StructureArray\n");
 }
 
+String StructureArray::getID() const
+{
+	// NOTE: structure->getID() can return an empty string
+	return pstructure->getID() + "[]";
+}
+
 void StructureArray::toString(StringBuilder buffer,int indentLevel) const {
     if(indentLevel==0) {
         *buffer +=  "structure[]";
@@ -172,11 +219,11 @@ void StructureArray::deserialize(ByteBuffer *buffer, DeserializableControl *cont
     throw std::runtime_error("not valid operation, use FieldCreate::deserialize instead");
 }
 
-
-Structure::Structure (StringArray const & fieldNames,FieldConstPtrArray const & infields)
+Structure::Structure (StringArray const & fieldNames,FieldConstPtrArray const & infields, String inid)
 : Field(structure),
       fieldNames(fieldNames),
-      fields(infields)
+      fields(infields),
+      id(inid)
 {
     if(fieldNames.size()!=fields.size()) {
         throw std::invalid_argument("fieldNames.size()!=fields.size()");
@@ -203,6 +250,11 @@ Structure::Structure (StringArray const & fieldNames,FieldConstPtrArray const &
 Structure::~Structure() { }
 
 
+String Structure::getID() const
+{
+	return id;
+}
+
 FieldConstPtr  Structure::getField(String fieldName) const {
     size_t numberFields = fields.size();
     for(size_t i=0; i<numberFields; i++) {
@@ -225,7 +277,8 @@ size_t Structure::getFieldIndex(String fieldName) const {
 
 void Structure::toString(StringBuilder buffer,int indentLevel) const{
     *buffer += "structure";
-     toStringCommon(buffer,indentLevel+1);
+    if (!id.empty()) { *buffer += ' '; *buffer += id; };
+    toStringCommon(buffer,indentLevel+1);
 }
     
 void Structure::toStringCommon(StringBuilder buffer,int indentLevel) const{
@@ -291,6 +344,15 @@ StructureConstPtr FieldCreate::createStructure (
       return structure;
 }
 
+StructureConstPtr FieldCreate::createStructure (
+	String id,
+    StringArray const & fieldNames,FieldConstPtrArray const & fields) const
+{
+      StructureConstPtr structure(
+         new Structure(fieldNames,fields,id), Field::Deleter());
+      return structure;
+}
+
 StructureArrayConstPtr FieldCreate::createStructureArray(
     StructureConstPtr const & structure) const
 {
diff --git a/pvDataApp/pv/pvIntrospect.h b/pvDataApp/pv/pvIntrospect.h
index 38383dc..6097295 100644
--- a/pvDataApp/pv/pvIntrospect.h
+++ b/pvDataApp/pv/pvIntrospect.h
@@ -209,6 +209,11 @@ public:
      * @return The type.
      */
    Type getType() const{return m_fieldType;}
+   /**
+    * Get the identification string.
+    * @return The identification string, can be empty.
+    */
+   virtual String getID() const = 0;
     /**
      * Convert the scalarType to a string and add it to builder.
      * @param  builder The string builder.
@@ -268,9 +273,11 @@ public:
      * @param  indentLevel The number of blanks at the beginning of new lines.
      */
     virtual void toString(StringBuilder buf,int indentLevel) const;
-    
-    virtual void serialize(ByteBuffer *buffer, SerializableControl *flusher) const;
-    virtual void deserialize(ByteBuffer *buffer, DeserializableControl *flusher);
+
+    virtual String getID() const;
+
+    virtual void serialize(ByteBuffer *buffer, SerializableControl *control) const;
+    virtual void deserialize(ByteBuffer *buffer, DeserializableControl *control);
     
 protected:
     Scalar(ScalarType scalarType);
@@ -310,8 +317,10 @@ public:
      */
     virtual void toString(StringBuilder buf,int indentLevel) const;
     
-    virtual void serialize(ByteBuffer *buffer, SerializableControl *flusher) const;
-    virtual void deserialize(ByteBuffer *buffer, DeserializableControl *flusher);
+    virtual String getID() const;
+
+    virtual void serialize(ByteBuffer *buffer, SerializableControl *control) const;
+    virtual void deserialize(ByteBuffer *buffer, DeserializableControl *control);
     
 protected:
     /**
@@ -345,8 +354,10 @@ public:
      */
     virtual void toString(StringBuilder buf,int indentLevel=0) const;
     
-    virtual void serialize(ByteBuffer *buffer, SerializableControl *flusher) const;
-    virtual void deserialize(ByteBuffer *buffer, DeserializableControl *flusher);
+    virtual String getID() const;
+
+    virtual void serialize(ByteBuffer *buffer, SerializableControl *control) const;
+    virtual void deserialize(ByteBuffer *buffer, DeserializableControl *control);
 
 protected:
     /**
@@ -431,15 +442,18 @@ public:
      */
     virtual void toString(StringBuilder buf,int indentLevel) const;
     
-    virtual void serialize(ByteBuffer *buffer, SerializableControl *flusher) const;
-    virtual void deserialize(ByteBuffer *buffer, DeserializableControl *flusher);
+    virtual String getID() const;
+
+    virtual void serialize(ByteBuffer *buffer, SerializableControl *control) const;
+    virtual void deserialize(ByteBuffer *buffer, DeserializableControl *control);
     
 protected:
-   Structure(StringArray const & fieldNames, FieldConstPtrArray const & fields);
+   Structure(StringArray const & fieldNames, FieldConstPtrArray const & fields, String id = "");
 private:
     void toStringCommon(StringBuilder buf,int indentLevel) const;
     StringArray fieldNames;
     FieldConstPtrArray fields;
+    String id;
    friend class FieldCreate;
 };
 
@@ -474,13 +488,24 @@ public:
     StructureArrayConstPtr createStructureArray(StructureConstPtr const & structure) const;
     /**
      * Create a {@code Structure} field.
-     * @param fieldNames The array of {@code fieldNames} for the structure
+     * @param fieldNames The array of {@code fieldNames} for the structure.
      * @param fields The array of {@code fields} for the structure.
      * @return a {@code Structure} interface for the newly created object.
      */
     StructureConstPtr createStructure (
         StringArray const & fieldNames,
         FieldConstPtrArray const & fields) const;
+    /**
+     * Create a {@code Structure} field with identification string.
+     * @param id The identification string for the structure.
+     * @param fieldNames The array of {@code fieldNames} for the structure.
+     * @param fields The array of {@code fields} for the structure.
+     * @return a {@code Structure} interface for the newly created object.
+     */
+    StructureConstPtr createStructure (
+    	String id,
+        StringArray const & fieldNames,
+        FieldConstPtrArray const & fields) const;
     /**
      * Append a field to a structure.
      * @param structure The structure to which the field is appended.
diff --git a/testApp/misc/testSerialization.cpp b/testApp/misc/testSerialization.cpp
index 67f784d..4f4f8a7 100644
--- a/testApp/misc/testSerialization.cpp
+++ b/testApp/misc/testSerialization.cpp
@@ -573,6 +573,37 @@ void testStructure(std::ostream& ofile) {
     ofile<<"!!!  PASSED\n\n";
 }
 
+
+
+void testStructureId(std::ostream& ofile) {
+    ofile<<"Testing structureID...\n";
+
+    FieldCreatePtr fieldCreate = getFieldCreate();
+
+    StringArray fieldNames;
+    fieldNames.push_back("longField");
+    fieldNames.push_back("intField");
+
+    FieldConstPtrArray fields;
+    fields.push_back(fieldCreate->createScalar(pvLong));
+    fields.push_back(fieldCreate->createScalar(pvInt));
+
+    StructureConstPtr structureWithNoId = fieldCreate->createStructure(fieldNames, fields);
+    StructureConstPtr structure1 = fieldCreate->createStructure("id1", fieldNames, fields);
+    StructureConstPtr structure2 = fieldCreate->createStructure("id2", fieldNames, fields);
+
+
+    assert(structureWithNoId!=structure1);
+    assert(structure1!=structure2);
+
+    //serializationTest(structure1);
+
+    PVStructurePtr pvStructure = getPVDataCreate()->createPVStructure(structure1);
+    serializationTest(pvStructure);
+
+    ofile<<"!!!  PASSED\n\n";
+}
+
 void serializatioTest(FieldConstPtr const & field)
 {
 	buffer->clear();