diff --git a/src/main/java/eu/europa/ted/eforms/sdk/entity/SdkField.java b/src/main/java/eu/europa/ted/eforms/sdk/entity/SdkField.java
index a6fa4c7..45b67ae 100644
--- a/src/main/java/eu/europa/ted/eforms/sdk/entity/SdkField.java
+++ b/src/main/java/eu/europa/ted/eforms/sdk/entity/SdkField.java
@@ -1,5 +1,8 @@
 package eu.europa.ted.eforms.sdk.entity;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 import java.util.Objects;
 import com.fasterxml.jackson.databind.JsonNode;
 import eu.europa.ted.eforms.xpath.XPathInfo;
@@ -15,7 +18,12 @@ public abstract class SdkField implements Comparable<SdkField> {
   private final boolean repeatable;
   private final String privacyCode;
   private final PrivacySettings privacySettings;
+  private final List<String> attributes;
+  private final String attributeOf;
+  private final String attributeName;
   private SdkNode parentNode;
+  private List<SdkField> attributeFields;
+  private SdkField attributeOfField;
   private XPathInfo xpathInfo;
 
   /**
@@ -111,6 +119,9 @@ protected SdkField(final String id, final String type, final String parentNodeId
     this.repeatable = repeatable;
     this.privacyCode = null;
     this.privacySettings = null;
+    this.attributes = Collections.emptyList();
+    this.attributeOf = null;
+    this.attributeName = null;
   }
 
   protected SdkField(final JsonNode fieldNode) {
@@ -124,6 +135,21 @@ protected SdkField(final JsonNode fieldNode) {
     final JsonNode privacyNode = fieldNode.get("privacy");
     this.privacyCode = privacyNode != null ? privacyNode.get("code").asText(null) : null;
     this.privacySettings = extractPrivacy(privacyNode);
+    this.attributes = extractAttributes(fieldNode);
+    this.attributeOf = fieldNode.has("attributeOf") ? fieldNode.get("attributeOf").asText(null) : null;
+    this.attributeName = fieldNode.has("attributeName") ? fieldNode.get("attributeName").asText(null) : null;
+  }
+
+  protected List<String> extractAttributes(final JsonNode fieldNode) {
+    final JsonNode attributesNode = fieldNode.get("attributes");
+    if (attributesNode == null || !attributesNode.isArray()) {
+      return Collections.emptyList();
+    }
+    List<String> result = new ArrayList<>();
+    for (JsonNode attr : attributesNode) {
+      result.add(attr.asText());
+    }
+    return Collections.unmodifiableList(result);
   }
 
   protected String extractCodelistId(final JsonNode fieldNode) {
@@ -193,6 +219,50 @@ public String getCodelistId() {
     return this.codelistId;
   }
 
+  public List<String> getAttributes() {
+    return this.attributes;
+  }
+
+  public String getAttributeOf() {
+    return this.attributeOf;
+  }
+
+  public String getAttributeName() {
+    return this.attributeName;
+  }
+
+  public List<SdkField> getAttributeFields() {
+    return this.attributeFields;
+  }
+
+  public void setAttributeFields(List<SdkField> attributeFields) {
+    this.attributeFields = Collections.unmodifiableList(attributeFields);
+  }
+
+  public SdkField getAttributeOfField() {
+    return this.attributeOfField;
+  }
+
+  public void setAttributeOfField(SdkField attributeOfField) {
+    this.attributeOfField = attributeOfField;
+  }
+
+  /**
+   * Returns the attribute field with the given XML attribute name (e.g. "unitCode", "listName"),
+   * or null if this field has no such attribute.
+   */
+  public SdkField getAttributeField(String attrName) {
+    if (this.attributeFields == null) {
+      return null;
+    }
+    for (SdkField attrField : this.attributeFields) {
+      if (attrName.equals(attrField.getAttributeName())) {
+        return attrField;
+      }
+    }
+    return null;
+  }
+
   public boolean isRepeatable() {
     return this.repeatable;
   }
diff --git a/src/main/java/eu/europa/ted/eforms/sdk/repository/SdkDataTypeRepository.java b/src/main/java/eu/europa/ted/eforms/sdk/repository/SdkDataTypeRepository.java
index 5f379c4..27cd9bd 100644
--- a/src/main/java/eu/europa/ted/eforms/sdk/repository/SdkDataTypeRepository.java
+++ b/src/main/java/eu/europa/ted/eforms/sdk/repository/SdkDataTypeRepository.java
@@ -50,6 +50,7 @@ public static SdkDataTypeRepository createDefault() {
     repository.addType("number", "-1");
     repository.addType("amount", "-1");
     repository.addType("measure", "-1");
+    repository.addType("duration", "-1");
 
     return repository;
   }
diff --git a/src/main/java/eu/europa/ted/eforms/sdk/repository/SdkFieldRepository.java b/src/main/java/eu/europa/ted/eforms/sdk/repository/SdkFieldRepository.java
index 6edebfd..a06f6aa 100644
--- a/src/main/java/eu/europa/ted/eforms/sdk/repository/SdkFieldRepository.java
+++ b/src/main/java/eu/europa/ted/eforms/sdk/repository/SdkFieldRepository.java
@@ -1,6 +1,8 @@
 package eu.europa.ted.eforms.sdk.repository;
 
 import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import eu.europa.ted.eforms.sdk.SdkConstants;
@@ -43,7 +45,7 @@ protected void populateMap(final JsonNode json, final Object... context)
       }
     }
 
-    // Second pass: resolve privacy field references
+    // Second pass: resolve cross-field references
     for (final SdkField sdkField : this.values()) {
       if (sdkField.getPrivacySettings() != null) {
         SdkField.PrivacySettings privacy = sdkField.getPrivacySettings();
@@ -62,6 +64,21 @@ protected void populateMap(final JsonNode json, final Object... context)
           privacy.setPublicationDateField(this.get(privacy.getPublicationDateFieldId()));
         }
       }
+
+      if (!sdkField.getAttributes().isEmpty()) {
+        List<SdkField> attrFields = new ArrayList<>();
+        for (String attrFieldId : sdkField.getAttributes()) {
+          SdkField attrField = this.get(attrFieldId);
+          if (attrField != null) {
+            attrFields.add(attrField);
+          }
+        }
+        sdkField.setAttributeFields(attrFields);
+      }
+
+      if (sdkField.getAttributeOf() != null) {
+        sdkField.setAttributeOfField(this.get(sdkField.getAttributeOf()));
+      }
     }
   }
 }