diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/common/IntegrationEntity.java b/navalplanner-business/src/main/java/org/navalplanner/business/common/IntegrationEntity.java
new file mode 100644
index 000000000..984ccdd32
--- /dev/null
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/common/IntegrationEntity.java
@@ -0,0 +1,152 @@
+/*
+ * This file is part of ###PROJECT_NAME###
+ *
+ * Copyright (C) 2009 Fundación para o Fomento da Calidade Industrial e
+ *                    Desenvolvemento Tecnolóxico de Galicia
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.navalplanner.business.common;
+
+import java.util.UUID;
+
+import org.apache.commons.lang.StringUtils;
+import org.hibernate.validator.AssertTrue;
+import org.hibernate.validator.NotEmpty;
+import org.navalplanner.business.common.daos.IIntegrationEntityDAO;
+import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
+
+/**
+ * Base class for all entities to be sent/received to/from other applications.
+ * These entities have a "code" attribute, which unlike "id" is unique among
+ * the applications to be integrated ("id" is only unique inside
+ * "navalplanner").
+ *
+ * @author Fernando Bellas Permuy <fbellas@udc.es>
+ */
+public abstract class IntegrationEntity extends BaseEntity {
+
+    private String code;
+
+    @NotEmpty(message="code not specified")
+    public String getCode() {
+        return code;
+    }
+
+    public void setCode(String code) {
+        this.code = code;
+    }
+
+    /**
+     * This creation method must be used when we want to create an instance
+     * specifying a specific code (e.g. provided by the end-user or an external
+     * application).
+     */
+    protected static <T extends IntegrationEntity> T create(
+        T integrationEntity, String code) {
+
+        BaseEntity.create(integrationEntity);
+        integrationEntity.code = code;
+
+        return integrationEntity;
+
+    }
+
+    /**
+     * This creation method must be used when we want the creation method to
+     * automatically generate a code. This is a Template method which delegates
+     * code generation by calling on <code>generateCode()</code>.
+     */
+    protected static <T extends IntegrationEntity> T create(
+        T integrationEntity) {
+
+        BaseEntity.create(integrationEntity);
+        integrationEntity.code = generateCode();
+
+        return integrationEntity;
+
+    }
+
+    /**
+     * This method is called by <code>create(IntegrationEntity)</code>. It
+     * returns an unique String UUID. The current implementation is good enough
+     * for entities created in test classes. However, concrete classes
+     * interested in automatically generating descriptive identifiers when
+     * calling <code>create(IntegrationEntity)</code>, will probably redefine
+     * this method.
+     */
+    protected static String generateCode() {
+        return UUID.randomUUID().toString();
+    }
+
+    /**
+     * It checks if there exists another integration entity of the same type
+     * with the same code. This method is a Template method that calls on
+     * the private method <code>findIntegrationEntityDAO</code>, which in turn
+     * calls on the abstract method <code>getIntegrationEntityDAO()</code>.
+     */
+    @AssertTrue(message="code is already being used")
+    public boolean checkConstraintUniqueCode() {
+
+        /* Check if it makes sense to check the constraint .*/
+        if (!iCodeSpecified()) {
+            return true;
+        }
+
+        /* Check the constraint. */
+        IIntegrationEntityDAO<? extends IntegrationEntity>
+            integrationEntityDAO = findIntegrationEntityDAO();
+
+        if (isNewObject()) {
+            return !integrationEntityDAO.existsByCodeAnotherTransaction(code);
+        } else {
+            try {
+                IntegrationEntity entity =
+                    integrationEntityDAO.findByCodeAnotherTransaction(code);
+                return entity.getId().equals(getId());
+            } catch (InstanceNotFoundException e) {
+                return true;
+            }
+        }
+
+    }
+
+    /**
+     * It returns the DAO of this entity.
+     */
+    protected abstract IIntegrationEntityDAO<? extends IntegrationEntity>
+        getIntegrationEntityDAO();
+
+    private IIntegrationEntityDAO<? extends IntegrationEntity>
+        findIntegrationEntityDAO() {
+
+        IIntegrationEntityDAO<? extends IntegrationEntity>
+            integrationEntityDAO = getIntegrationEntityDAO();
+
+        if (!integrationEntityDAO.getEntityClass().equals(this.getClass())) {
+            throw new RuntimeException(this.getClass().getName() + "::" +
+                "getIntegrationEntityDAO returns an incompatible " +
+                "DAO: " + integrationEntityDAO.getClass().getName());
+        } else {
+            return integrationEntityDAO;
+        }
+
+    }
+
+    private boolean iCodeSpecified() {
+        return !StringUtils.isBlank(code);
+    }
+
+}
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/GenericDAOHibernate.java b/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/GenericDAOHibernate.java
index d8c30de54..b65992100 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/GenericDAOHibernate.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/GenericDAOHibernate.java
@@ -79,6 +79,10 @@ public class GenericDAOHibernate<E extends BaseEntity,
         return sessionFactory.getCurrentSession();
     }
 
+    public Class<E> getEntityClass() {
+        return entityClass;
+    }
+
     /**
      * It's necessary to save and validate later.
      *
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/IGenericDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/IGenericDAO.java
index 27b8c1de5..06f52bebb 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/IGenericDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/IGenericDAO.java
@@ -39,6 +39,8 @@ import org.springframework.dao.OptimisticLockingFailureException;
  */
 public interface IGenericDAO <E, PK extends Serializable>{
 
+    public Class<E> getEntityClass();
+
     /**
      * It inserts the object passed as a parameter in the ORM session, planning
      * it for updating (even though it is not modified before or after the call
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/IIntegrationEntityDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/IIntegrationEntityDAO.java
new file mode 100644
index 000000000..f6f88ce69
--- /dev/null
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/IIntegrationEntityDAO.java
@@ -0,0 +1,47 @@
+/*
+ * This file is part of ###PROJECT_NAME###
+ *
+ * Copyright (C) 2009 Fundación para o Fomento da Calidade Industrial e
+ *                    Desenvolvemento Tecnolóxico de Galicia
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.navalplanner.business.common.daos;
+
+import org.navalplanner.business.common.IntegrationEntity;
+import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
+
+/**
+ * Common DAO interface for all entities used in application integration. All
+ * DAO interfaces of entities used in application integration must extend from
+ * this interface.
+ *
+ * @author Fernando Bellas Permuy <fbellas@udc.es>
+ */
+public interface IIntegrationEntityDAO<E extends IntegrationEntity>
+    extends IGenericDAO<E, Long> {
+
+    public boolean existsByCode(String code);
+
+    public boolean existsByCodeAnotherTransaction(String code);
+
+    public E findByCode(String code) throws InstanceNotFoundException;
+
+    public E findByCodeAnotherTransaction(String code)
+        throws InstanceNotFoundException;
+
+    public E findExistingEntityByCode(String code);
+
+}
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/IntegrationEntityDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/IntegrationEntityDAO.java
new file mode 100644
index 000000000..592d772b8
--- /dev/null
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/common/daos/IntegrationEntityDAO.java
@@ -0,0 +1,92 @@
+/*
+ * This file is part of ###PROJECT_NAME###
+ *
+ * Copyright (C) 2009 Fundación para o Fomento da Calidade Industrial e
+ *                    Desenvolvemento Tecnolóxico de Galicia
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.navalplanner.business.common.daos;
+
+import org.hibernate.criterion.Restrictions;
+import org.navalplanner.business.common.IntegrationEntity;
+import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
+import org.springframework.transaction.annotation.Propagation;
+import org.springframework.transaction.annotation.Transactional;
+
+/**
+ * Default implementation of <code>IIntegrationEntityDAO</code>. DAOs of
+ * entities used in application integration may extend from this interface.
+ *
+ * @author Fernando Bellas Permuy <fbellas@udc.es>
+ */
+public class IntegrationEntityDAO<E extends IntegrationEntity>
+    extends GenericDAOHibernate<E, Long> implements IIntegrationEntityDAO<E> {
+
+    @Override
+    public boolean existsByCode(String code) {
+
+        try {
+            findByCode(code);
+            return true;
+        } catch (InstanceNotFoundException e) {
+            return false;
+        }
+
+    }
+
+    @Override
+    @Transactional(readOnly = true, propagation = Propagation.REQUIRES_NEW)
+    public boolean existsByCodeAnotherTransaction(String code) {
+        return existsByCode(code);
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public E findByCode(String code) throws InstanceNotFoundException {
+
+        E entity = (E) getSession().createCriteria(getEntityClass()).add(
+            Restrictions.eq("code", code).ignoreCase()).uniqueResult();
+
+        if (entity == null) {
+            throw new InstanceNotFoundException(
+                code, getEntityClass().getName());
+        } else {
+            return entity;
+        }
+
+    }
+
+    @Override
+    @Transactional(readOnly = true, propagation = Propagation.REQUIRES_NEW)
+    public E findByCodeAnotherTransaction(String code)
+        throws InstanceNotFoundException {
+
+        return findByCode(code);
+
+    }
+
+    @Override
+    public E findExistingEntityByCode(String code) {
+
+        try {
+            return findByCode(code);
+        } catch (InstanceNotFoundException e) {
+            throw new RuntimeException(e);
+        }
+
+    }
+
+}
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/CriterionDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/CriterionDAO.java
index 1e7a73c6f..750bc8e28 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/CriterionDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/CriterionDAO.java
@@ -27,7 +27,7 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.hibernate.Criteria;
 import org.hibernate.criterion.Restrictions;
-import org.navalplanner.business.common.daos.GenericDAOHibernate;
+import org.navalplanner.business.common.daos.IntegrationEntityDAO;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.resources.entities.Criterion;
 import org.navalplanner.business.resources.entities.ICriterionType;
@@ -46,8 +46,8 @@ import org.springframework.transaction.annotation.Transactional;
  */
 @Repository
 @Scope(BeanDefinition.SCOPE_SINGLETON)
-public class CriterionDAO extends GenericDAOHibernate<Criterion, Long>
-        implements ICriterionDAO {
+public class CriterionDAO extends IntegrationEntityDAO<Criterion>
+    implements ICriterionDAO {
 
     private static final Log log = LogFactory.getLog(CriterionDAO.class);
 
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/CriterionTypeDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/CriterionTypeDAO.java
index 1ad2b38ca..66fa16edb 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/CriterionTypeDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/CriterionTypeDAO.java
@@ -26,7 +26,7 @@ import java.util.List;
 import org.apache.commons.lang.Validate;
 import org.hibernate.Criteria;
 import org.hibernate.criterion.Restrictions;
-import org.navalplanner.business.common.daos.GenericDAOHibernate;
+import org.navalplanner.business.common.daos.IntegrationEntityDAO;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.resources.entities.CriterionType;
 import org.navalplanner.business.resources.entities.ResourceEnum;
@@ -41,8 +41,8 @@ import org.springframework.transaction.annotation.Transactional;
  */
 
 @Component
-public class CriterionTypeDAO extends GenericDAOHibernate<CriterionType, Long>
-        implements ICriterionTypeDAO {
+public class CriterionTypeDAO extends IntegrationEntityDAO<CriterionType>
+    implements ICriterionTypeDAO {
 
     @Override
     public List<CriterionType> findByName(CriterionType criterionType) {
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionDAO.java
index ce2447293..0c346fedd 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionDAO.java
@@ -22,7 +22,7 @@ package org.navalplanner.business.resources.daos;
 
 import java.util.List;
 
-import org.navalplanner.business.common.daos.IGenericDAO;
+import org.navalplanner.business.common.daos.IIntegrationEntityDAO;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.resources.entities.Criterion;
 import org.navalplanner.business.resources.entities.ICriterionType;
@@ -33,8 +33,9 @@ import org.springframework.transaction.annotation.Transactional;
  *
  * @author Óscar González Fernández <ogonzalez@igalia.com>
  * @author Diego Pino García <dpino@igalia.com>
+ * @author Fernando Bellas Permuy <fbellas@udc.es>
  */
-public interface ICriterionDAO extends IGenericDAO<Criterion, Long> {
+public interface ICriterionDAO extends IIntegrationEntityDAO<Criterion> {
 
     public void removeByNameAndType(Criterion criterion);
 
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionTypeDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionTypeDAO.java
index a9a1689aa..7664c8cdf 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionTypeDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/daos/ICriterionTypeDAO.java
@@ -23,7 +23,7 @@ package org.navalplanner.business.resources.daos;
 import java.util.Collection;
 import java.util.List;
 
-import org.navalplanner.business.common.daos.IGenericDAO;
+import org.navalplanner.business.common.daos.IIntegrationEntityDAO;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.resources.entities.CriterionType;
 import org.navalplanner.business.resources.entities.ResourceEnum;
@@ -33,7 +33,8 @@ import org.navalplanner.business.resources.entities.ResourceEnum;
  * @author Diego Pino Garcia <dpino@igalia.com>
  * @author Fernando Bellas Permuy <fbellas@udc.es>
  */
-public interface ICriterionTypeDAO extends IGenericDAO<CriterionType, Long> {
+public interface ICriterionTypeDAO
+    extends IIntegrationEntityDAO<CriterionType> {
 
     CriterionType findUniqueByName(String name)
             throws InstanceNotFoundException;
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Criterion.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Criterion.java
index d6fb55f83..1e56a7d7e 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Criterion.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Criterion.java
@@ -32,20 +32,22 @@ import org.hibernate.validator.AssertTrue;
 import org.hibernate.validator.NotEmpty;
 import org.hibernate.validator.NotNull;
 import org.hibernate.validator.Valid;
-import org.navalplanner.business.common.BaseEntity;
+import org.navalplanner.business.common.IntegrationEntity;
+import org.navalplanner.business.common.Registry;
 import org.navalplanner.business.requirements.entities.CriterionRequirement;
+import org.navalplanner.business.resources.daos.ICriterionDAO;
 
 /**
  * A criterion stored in the database <br />
  * @author Óscar González Fernández <ogonzalez@igalia.com>
  * @author Fernando Bellas Permuy <fbellas@udc.es>
  */
-public class Criterion extends BaseEntity implements ICriterion {
+public class Criterion extends IntegrationEntity implements ICriterion {
 
-    public static Criterion createUnvalidated(String name, CriterionType type,
-        Criterion parent, boolean active) {
+    public static Criterion createUnvalidated(String code, String name,
+        CriterionType type, Criterion parent, boolean active) {
 
-        Criterion criterion = create(new Criterion());
+        Criterion criterion = create(new Criterion(), code);
 
         criterion.name = name;
         criterion.type = type;
@@ -57,26 +59,19 @@ public class Criterion extends BaseEntity implements ICriterion {
     }
 
     public static Criterion create(CriterionType type) {
-        Criterion criterion = new Criterion(type);
-        criterion.setNewObject(true);
-        return criterion;
+        return create(new Criterion(type));
     }
 
     public static Criterion create(String name, CriterionType type) {
-        Criterion criterion = new Criterion(name, type);
-        criterion.setNewObject(true);
-        return criterion;
+        return create(new Criterion(name, type));
     }
 
-    @NotEmpty(message="criterion name not specified")
     private String name;
 
-    @NotNull(message="criterion type not specified")
     private CriterionType type;
 
     private Criterion parent = null;
 
-    @Valid
     private Set<Criterion> children =  new HashSet<Criterion>();
 
     private boolean active = true;
@@ -127,6 +122,7 @@ public class Criterion extends BaseEntity implements ICriterion {
                 Interval.range(start, end)).result().isEmpty();
     }
 
+    @NotEmpty(message="criterion name not specified")
     public String getName() {
         return name;
     }
@@ -135,6 +131,7 @@ public class Criterion extends BaseEntity implements ICriterion {
         this.name = name;
     }
 
+    @NotNull(message="criterion type not specified")
     public CriterionType getType() {
         return type;
     }
@@ -163,6 +160,7 @@ public class Criterion extends BaseEntity implements ICriterion {
         this.parent = parent;
     }
 
+    @Valid
     public Set<Criterion> getChildren() {
         return children;
     }
@@ -213,4 +211,9 @@ public class Criterion extends BaseEntity implements ICriterion {
         criterionRequirement.setCriterion(this);
         this.criterionRequirements.add(criterionRequirement);
     }
+
+    @Override
+    protected ICriterionDAO getIntegrationEntityDAO() {
+        return Registry.getCriterionDAO();
+    }
 }
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/CriterionType.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/CriterionType.java
index 95113ffea..461dd948e 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/CriterionType.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/CriterionType.java
@@ -28,7 +28,7 @@ import org.apache.commons.lang.builder.EqualsBuilder;
 import org.hibernate.validator.AssertTrue;
 import org.hibernate.validator.NotEmpty;
 import org.hibernate.validator.Valid;
-import org.navalplanner.business.common.BaseEntity;
+import org.navalplanner.business.common.IntegrationEntity;
 import org.navalplanner.business.common.Registry;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.resources.daos.ICriterionTypeDAO;
@@ -41,22 +41,20 @@ import org.springframework.stereotype.Component;
  * @author Fernando Bellas Permuy <fbellas@udc.es>
  */
 @Component
-public class CriterionType extends BaseEntity implements
+public class CriterionType extends IntegrationEntity implements
         ICriterionType<Criterion> {
 
     public static CriterionType create() {
-        CriterionType criterionType = new CriterionType();
-        criterionType.setNewObject(true);
-        return criterionType;
+        return create(new CriterionType());
     }
 
 
-    public static CriterionType createUnvalidated(String name,
+    public static CriterionType createUnvalidated(String code, String name,
         String description, Boolean allowHierarchy,
         Boolean allowSimultaneousCriterionsPerResource, Boolean enabled,
         ResourceEnum resource) {
 
-        CriterionType criterionType = create(new CriterionType());
+        CriterionType criterionType = create(new CriterionType(), code);
 
         criterionType.name = name;
         criterionType.description = description;
@@ -71,21 +69,18 @@ public class CriterionType extends BaseEntity implements
     }
 
     public static CriterionType create(String name,String description) {
-        CriterionType criterionType = new CriterionType(name,description);
-        criterionType.setNewObject(true);
-        return criterionType;
+        return create(new CriterionType(name,description));
     }
 
     public static CriterionType create(String name,String description,
             boolean allowHierarchy,boolean allowSimultaneousCriterionsPerResource,
             boolean enabled,ResourceEnum resource) {
-        CriterionType criterionType = new CriterionType(name,description, allowHierarchy,
-                allowSimultaneousCriterionsPerResource,enabled,resource);
-        criterionType.setNewObject(true);
-        return criterionType;
+
+        return create(new CriterionType(name,description, allowHierarchy,
+            allowSimultaneousCriterionsPerResource,enabled,resource));
+
     }
 
-    @NotEmpty(message="criterion type name not specified")
     private String name;
 
     private String description;
@@ -98,7 +93,6 @@ public class CriterionType extends BaseEntity implements
 
     private ResourceEnum resource = ResourceEnum.getDefault();
 
-    @Valid
     private Set<Criterion> criterions = new HashSet<Criterion>();
 
     private int numCriterions;
@@ -146,6 +140,7 @@ public class CriterionType extends BaseEntity implements
     }
 
     @Override
+    @NotEmpty(message="criterion type name not specified")
     public String getName() {
         return name;
     }
@@ -154,6 +149,7 @@ public class CriterionType extends BaseEntity implements
         this.name = name;
     }
 
+    @Valid
     public Set<Criterion> getCriterions() {
         return criterions;
     }
@@ -378,4 +374,10 @@ public class CriterionType extends BaseEntity implements
         return !StringUtils.isBlank(name);
     }
 
+
+    @Override
+    protected ICriterionTypeDAO getIntegrationEntityDAO() {
+        return Registry.getCriterionTypeDAO();
+    }
+
 }
diff --git a/navalplanner-business/src/main/resources/org/navalplanner/business/resources/entities/Resources.hbm.xml b/navalplanner-business/src/main/resources/org/navalplanner/business/resources/entities/Resources.hbm.xml
index 4681319ab..cdabb89b8 100644
--- a/navalplanner-business/src/main/resources/org/navalplanner/business/resources/entities/Resources.hbm.xml
+++ b/navalplanner-business/src/main/resources/org/navalplanner/business/resources/entities/Resources.hbm.xml
@@ -66,6 +66,7 @@
       </generator>
     </id>
     <version name="version" access="property" type="long" />
+    <property name="code" access="property" not-null="true" unique="true"/>
     <property access="field" name="name"/>
     <property access="field" name="active"/>
     <many-to-one access="field" name="type" column="id_criterion_type" not-null="true" />
@@ -110,6 +111,7 @@
       <generator class="hilo"/>
     </id>
     <version name="version" access="property" type="long" />
+    <property name="code" access="property" not-null="true" unique="true"/>
     <property name="name" unique="true"/>
     <property name="description"/>
     <property name="allowSimultaneousCriterionsPerResource"/>
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/api/InstanceConstraintViolationsDTO.java b/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/api/InstanceConstraintViolationsDTO.java
index 728497806..c0d90dbbb 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/api/InstanceConstraintViolationsDTO.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/api/InstanceConstraintViolationsDTO.java
@@ -35,16 +35,33 @@ import javax.xml.bind.annotation.XmlElement;
  */
 public class InstanceConstraintViolationsDTO {
 
+    public final static String NUM_ITEM_ATTRIBUTE_NAME = "num-item";
+    public final static String CODE_ATTRIBUTE_NAME =
+        IntegrationEntityDTO.CODE_ATTRIBUTE_NAME;
+    public final static String ENTITY_TYPE_ATTRIBUTE_NAME = "entity-type";
+
+    @Deprecated
     public final static String INSTANCE_ID_ATTRIBUTE_NAME = "instance-id";
 
+    @Deprecated
     @XmlAttribute(name=INSTANCE_ID_ATTRIBUTE_NAME)
     public String instanceId;
 
+    @XmlAttribute(name=NUM_ITEM_ATTRIBUTE_NAME)
+    public Long numItem;
+
+    @XmlAttribute(name=CODE_ATTRIBUTE_NAME)
+    public String code;
+
+    @XmlAttribute(name=ENTITY_TYPE_ATTRIBUTE_NAME)
+    public String entityType;
+
     @XmlElement(name="constraint-violation")
     public List<ConstraintViolationDTO> constraintViolations;
 
     public InstanceConstraintViolationsDTO() {}
 
+    @Deprecated
     public InstanceConstraintViolationsDTO(String instanceId,
         List<ConstraintViolationDTO> constraintViolations) {
 
@@ -53,6 +70,18 @@ public class InstanceConstraintViolationsDTO {
 
     }
 
+    public InstanceConstraintViolationsDTO(
+        InstanceConstraintViolationsDTOId instanceId,
+        List<ConstraintViolationDTO> constraintViolations) {
+
+        this.numItem = instanceId.getNumItem();
+        this.code = instanceId.getCode();
+        this.entityType = instanceId.getEntityType();
+        this.constraintViolations = constraintViolations;
+
+    }
+
+    @Deprecated
     public static InstanceConstraintViolationsDTO create(String instanceId,
         String message) {
 
@@ -66,6 +95,19 @@ public class InstanceConstraintViolationsDTO {
 
     }
 
+    public static InstanceConstraintViolationsDTO create(
+        InstanceConstraintViolationsDTOId instanceId, String message) {
+
+        List<ConstraintViolationDTO> constraintViolations =
+            new ArrayList<ConstraintViolationDTO>();
+
+        constraintViolations.add(new ConstraintViolationDTO(null, message));
+
+        return new InstanceConstraintViolationsDTO(instanceId,
+            constraintViolations);
+
+    }
+
     @Override
     public String toString() {
 
@@ -75,6 +117,12 @@ public class InstanceConstraintViolationsDTO {
         printWriter.println("** " + INSTANCE_ID_ATTRIBUTE_NAME + " = " +
             instanceId + " **");
 
+        printWriter.println("** " +
+            NUM_ITEM_ATTRIBUTE_NAME + " = " + numItem + " - " +
+            CODE_ATTRIBUTE_NAME + " = " + code + " - " +
+            ENTITY_TYPE_ATTRIBUTE_NAME + " = " + entityType +
+            " **");
+
         for (ConstraintViolationDTO i : constraintViolations) {
             printWriter.println(i);
         }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/api/InstanceConstraintViolationsDTOId.java b/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/api/InstanceConstraintViolationsDTOId.java
new file mode 100644
index 000000000..08ebed23a
--- /dev/null
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/api/InstanceConstraintViolationsDTOId.java
@@ -0,0 +1,55 @@
+/*
+ * This file is part of ###PROJECT_NAME###
+ *
+ * Copyright (C) 2009 Fundación para o Fomento da Calidade Industrial e
+ *                    Desenvolvemento Tecnolóxico de Galicia
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.navalplanner.ws.common.api;
+
+/**
+ * Identifier for an instance causing a list of constraint violations.
+ *
+ * @author Fernando Bellas Permuy <fbellas@udc.es>
+ */
+public class InstanceConstraintViolationsDTOId {
+
+    private Long numItem;
+    private String code;
+    private String entityType;
+
+    public InstanceConstraintViolationsDTOId(Long numItem, String code,
+        String entityType) {
+
+        this.numItem = numItem;
+        this.code = code;
+        this.entityType = entityType;
+
+    }
+
+    public Long getNumItem() {
+        return numItem;
+    }
+
+    public String getCode() {
+        return code;
+    }
+
+    public String getEntityType() {
+        return entityType;
+    }
+
+}
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/api/IntegrationEntityDTO.java b/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/api/IntegrationEntityDTO.java
new file mode 100644
index 000000000..b37432465
--- /dev/null
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/api/IntegrationEntityDTO.java
@@ -0,0 +1,62 @@
+/*
+ * This file is part of ###PROJECT_NAME###
+ *
+ * Copyright (C) 2009 Fundación para o Fomento da Calidade Industrial e
+ *                    Desenvolvemento Tecnolóxico de Galicia
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.navalplanner.ws.common.api;
+
+import java.util.UUID;
+
+import javax.xml.bind.annotation.XmlAttribute;
+
+/**
+ * DTO for <code>IntegrationEntity</code>. All DTOs corresponding to entities
+ * to be used in application integration must extend from this DTO.
+ *
+ * @author Fernando Bellas Permuy <fbellas@udc.es>
+ */
+public abstract class IntegrationEntityDTO {
+
+    public final static String CODE_ATTRIBUTE_NAME = "code";
+
+    @XmlAttribute(name=CODE_ATTRIBUTE_NAME)
+    public String code;
+
+    public IntegrationEntityDTO() {}
+
+    public IntegrationEntityDTO(String code) {
+        this.code = code;
+    }
+
+
+    /**
+     * It returns the String to use in
+     * <code>InstanceConstraintViolationsDTOId.entityType</code>.
+     */
+    public abstract String getEntityType();
+
+    /**
+     * This method is useful to implement constructors (in subclasses) that
+     * automatically generate a unique code. Such constructors are useful for
+     * the implementation of test cases that add new instances (such instances
+     * will have a unique code).
+     */
+    protected static String generateCode() {
+        return UUID.randomUUID().toString();
+    }
+
+}
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/impl/ConstraintViolationConverter.java b/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/impl/ConstraintViolationConverter.java
index 7640ea454..e432563c4 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/impl/ConstraintViolationConverter.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/impl/ConstraintViolationConverter.java
@@ -26,6 +26,7 @@ import java.util.List;
 import org.hibernate.validator.InvalidValue;
 import org.navalplanner.ws.common.api.ConstraintViolationDTO;
 import org.navalplanner.ws.common.api.InstanceConstraintViolationsDTO;
+import org.navalplanner.ws.common.api.InstanceConstraintViolationsDTOId;
 
 /**
  * Converter for constraint violations.
@@ -58,6 +59,7 @@ public class ConstraintViolationConverter {
 
     }
 
+    @Deprecated
     public final static InstanceConstraintViolationsDTO toDTO(String instanceId,
         InvalidValue[] invalidValues) {
 
@@ -73,4 +75,20 @@ public class ConstraintViolationConverter {
 
     }
 
+    public final static InstanceConstraintViolationsDTO toDTO(
+        InstanceConstraintViolationsDTOId instanceId,
+        InvalidValue[] invalidValues) {
+
+        List<ConstraintViolationDTO> constraintViolationDTOs =
+            new ArrayList<ConstraintViolationDTO>();
+
+        for (InvalidValue i : invalidValues) {
+            constraintViolationDTOs.add(toDTO(i));
+        }
+
+        return new InstanceConstraintViolationsDTO(instanceId,
+            constraintViolationDTOs);
+
+    }
+
 }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/impl/Util.java b/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/impl/Util.java
index 06fbd220e..6b8581e56 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/impl/Util.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/ws/common/impl/Util.java
@@ -25,14 +25,28 @@ import java.io.StringWriter;
 
 import org.apache.cxf.common.util.Base64Utility;
 import org.apache.cxf.jaxrs.client.WebClient;
+import org.navalplanner.ws.common.api.InstanceConstraintViolationsDTOId;
+import org.navalplanner.ws.common.api.IntegrationEntityDTO;
 
 /**
  * Utilities class related with web service.
  *
  * @author Manuel Rego Casasnovas <mrego@igalia.com>
+ * @author Fernando Bellas Permuy <fbellas@udc.es>
  */
 public class Util {
 
+    public static InstanceConstraintViolationsDTOId
+        generateInstanceConstraintViolationsDTOId(Long numItem,
+             IntegrationEntityDTO integrationEntityDTO) {
+
+        return new InstanceConstraintViolationsDTOId(numItem,
+            integrationEntityDTO.code,
+            integrationEntityDTO.getEntityType());
+
+    }
+
+    @Deprecated
     public static String generateInstanceId(int instanceNumber,
             String instanceIdentifier) {
         String instanceId = instanceNumber + "";
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/api/CriterionDTO.java b/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/api/CriterionDTO.java
index 798c9866b..56c189fc5 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/api/CriterionDTO.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/api/CriterionDTO.java
@@ -27,12 +27,16 @@ import javax.xml.bind.annotation.XmlAttribute;
 import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlElementWrapper;
 
+import org.navalplanner.ws.common.api.IntegrationEntityDTO;
+
 /**
  * DTO for <code>Criterion</code> entity.
  *
  * @author Fernando Bellas Permuy <fbellas@udc.es>
  */
-public class CriterionDTO {
+public class CriterionDTO extends IntegrationEntityDTO {
+
+    public final static String ENTITY_TYPE = "criterion";
 
     @XmlAttribute
     public String name;
@@ -46,13 +50,31 @@ public class CriterionDTO {
 
     public CriterionDTO() {}
 
-    public CriterionDTO(String name, boolean active,
+    public CriterionDTO(String code, String name, boolean active,
         List<CriterionDTO> children) {
 
+        super(code);
         this.name = name;
         this.active = active;
         this.children = children;
 
     }
 
+    /**
+     * This constructor automatically generates a unique code. It is intended
+     * to facilitate the implementation of test cases that add new instances
+     * (such instances will have a unique code).
+     */
+    public CriterionDTO(String name, boolean active,
+        List<CriterionDTO> children) {
+
+        this(generateCode(), name, active, children);
+
+    }
+
+    @Override
+    public String getEntityType() {
+        return ENTITY_TYPE;
+    }
+
 }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/api/CriterionTypeDTO.java b/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/api/CriterionTypeDTO.java
index 2b8e7211f..eed20c505 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/api/CriterionTypeDTO.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/api/CriterionTypeDTO.java
@@ -27,6 +27,7 @@ import javax.xml.bind.annotation.XmlAttribute;
 import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlElementWrapper;
 
+import org.navalplanner.ws.common.api.IntegrationEntityDTO;
 import org.navalplanner.ws.common.api.ResourceEnumDTO;
 
 /**
@@ -34,7 +35,9 @@ import org.navalplanner.ws.common.api.ResourceEnumDTO;
  *
  * @author Fernando Bellas Permuy <fbellas@udc.es>
  */
-public class CriterionTypeDTO {
+public class CriterionTypeDTO extends IntegrationEntityDTO {
+
+    public final static String ENTITY_TYPE = "criterion-type";
 
     @XmlAttribute
     public String name;
@@ -60,11 +63,12 @@ public class CriterionTypeDTO {
 
     public CriterionTypeDTO() {}
 
-    public CriterionTypeDTO(String name, String description,
+    public CriterionTypeDTO(String code, String name, String description,
         boolean allowHierarchy, boolean allowSimultaneousCriterionsPerResource,
         boolean enabled, ResourceEnumDTO resource,
         List<CriterionDTO> criterions) {
 
+        super(code);
         this.name = name;
         this.description = description;
         this.allowHierarchy = allowHierarchy;
@@ -76,4 +80,25 @@ public class CriterionTypeDTO {
 
     }
 
+    /**
+     * This constructor automatically generates a unique code. It is intended
+     * to facilitate the implementation of test cases that add new instances
+     * (such instances will have a unique code).
+     */
+    public CriterionTypeDTO(String name, String description,
+        boolean allowHierarchy, boolean allowSimultaneousCriterionsPerResource,
+        boolean enabled, ResourceEnumDTO resource,
+        List<CriterionDTO> criterions) {
+
+        this(generateCode(), name, description, allowHierarchy,
+            allowSimultaneousCriterionsPerResource, enabled, resource,
+            criterions);
+
+    }
+
+    @Override
+    public String getEntityType() {
+        return ENTITY_TYPE;
+    }
+
 }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/impl/CriterionConverter.java b/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/impl/CriterionConverter.java
index 00ef6d99b..f8924edfc 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/impl/CriterionConverter.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/impl/CriterionConverter.java
@@ -70,6 +70,7 @@ public final class CriterionConverter {
         }
 
         return new CriterionTypeDTO(
+            criterionType.getCode(),
             criterionType.getName(),
             criterionType.getDescription(),
             criterionType.allowHierarchy(),
@@ -93,8 +94,8 @@ public final class CriterionConverter {
             childrenDTOs = null;
         }
 
-        return new CriterionDTO(criterion.getName(), criterion.isActive(),
-            childrenDTOs);
+        return new CriterionDTO(criterion.getCode(), criterion.getName(),
+            criterion.isActive(), childrenDTOs);
 
     }
 
@@ -102,6 +103,7 @@ public final class CriterionConverter {
         CriterionTypeDTO criterionTypeDTO) {
 
         CriterionType criterionType = CriterionType.createUnvalidated(
+            StringUtils.trim(criterionTypeDTO.code),
             StringUtils.trim(criterionTypeDTO.name),
             StringUtils.trim(criterionTypeDTO.description),
             criterionTypeDTO.allowHierarchy,
@@ -139,6 +141,7 @@ public final class CriterionConverter {
         Criterion criterionParent) {
 
         Criterion criterion = Criterion.createUnvalidated(
+            StringUtils.trim(childDTO.code),
             StringUtils.trim(childDTO.name),
             criterionType, criterionParent, childDTO.active);
 
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/impl/CriterionServiceREST.java b/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/impl/CriterionServiceREST.java
index 808163236..4f5f52a70 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/impl/CriterionServiceREST.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/ws/resources/criterion/impl/CriterionServiceREST.java
@@ -76,7 +76,7 @@ public class CriterionServiceREST implements ICriterionService {
 
         List<InstanceConstraintViolationsDTO> instanceConstraintViolationsList =
             new ArrayList<InstanceConstraintViolationsDTO>();
-        int instanceNumber = 1;
+        Long numItem = new Long(1);
         Set<String> criterionTypeNames = new HashSet<String>();
 
         /* Process criterion types. */
@@ -98,8 +98,8 @@ public class CriterionServiceREST implements ICriterionService {
 
                 instanceConstraintViolationsDTO =
                     InstanceConstraintViolationsDTO.create(
-                        Util.generateInstanceId(instanceNumber,
-                            criterionTypeDTO.name),
+                        Util.generateInstanceConstraintViolationsDTOId(numItem,
+                            criterionTypeDTO),
                         _("criterion type name is used by another criterion " +
                             "type being imported"));
 
@@ -138,8 +138,8 @@ public class CriterionServiceREST implements ICriterionService {
                 } catch (ValidationException e) {
                     instanceConstraintViolationsDTO =
                         ConstraintViolationConverter.toDTO(
-                            Util.generateInstanceId(instanceNumber,
-                                criterionTypeDTO.name),
+                            Util.generateInstanceConstraintViolationsDTOId(
+                                numItem, criterionTypeDTO),
                             e.getInvalidValues());
                 }
 
@@ -151,7 +151,7 @@ public class CriterionServiceREST implements ICriterionService {
                     instanceConstraintViolationsDTO);
             }
 
-            instanceNumber++;
+            numItem++;
 
         }
 
diff --git a/scripts/rest-clients/criterion-types-sample.xml b/scripts/rest-clients/criterion-types-sample.xml
index 4006f58f3..b270cf83d 100644
--- a/scripts/rest-clients/criterion-types-sample.xml
+++ b/scripts/rest-clients/criterion-types-sample.xml
@@ -3,87 +3,87 @@
 <criterion-type-list xmlns="http://rest.ws.navalplanner.org">
 
     <!-- Several errors: see comments -->
-    <criterion-type name="ct-1" description="ct-1 desc"
+    <criterion-type code="ct-1" name="ct-1" description="ct-1 desc"
         allow-hierarchy="false"
         allow-simultaneous-criterions-per-resource="true" enabled="true"
         resource="RESOURCE">
 
         <criterion-list>
             <!-- Missing criterion name -->
-            <criterion active="true"/>
-            <criterion name="c2" active="true">
+            <criterion code="ct-1-c1" active="true"/>
+            <criterion code="ct-1-c2" name="c2" active="true">
                 <!-- Criterion hierarchy is not allowed -->
                 <children>
-                    <criterion name="c2-1" active="true">
+                    <criterion code="ct-1-c2-1" name="c2-1" active="true">
                         <children>
-                            <criterion name="c2-1-1" active="false"/>
-                            <criterion name="c2-1-2" active="true"/>
+                            <criterion code="ct-1-c2-1-1" name="c2-1-1" active="false"/>
+                            <criterion code="ct-1-c2-1-2" name="c2-1-2" active="true"/>
                         </children>
                     </criterion>
                     <!-- Repeated criterion name -->
-                    <criterion name=" C2-1 " active="true"/>
+                    <criterion code="ct-1-c2-2" name=" C2-1 " active="true"/>
                 </children>
             </criterion>
         </criterion-list>
     </criterion-type>
 
     <!-- Missing criterion type name -->
-    <criterion-type description="ct-2 desc" allow-hierarchy="true"
+    <criterion-type code="ct-2" description="ct-2 desc" allow-hierarchy="true"
         allow-simultaneous-criterions-per-resource="true" enabled="true"
         resource="RESOURCE">
         <criterion-list>
-            <criterion name="c1" active="true"/>
-            <criterion name="c2" active="true"/>
+            <criterion code="ct-2-c1" name="c1" active="true"/>
+            <criterion code="ct-2-c2" name="c2" active="true"/>
         </criterion-list>
     </criterion-type>
 
     <!-- OK -->
-    <criterion-type name="ct-4" description="ct-4 desc" allow-hierarchy="true"
-        allow-simultaneous-criterions-per-resource="true" enabled="true"
-        resource="RESOURCE">
+    <criterion-type code="ct-4" name="ct-4" description="ct-4 desc"
+        allow-hierarchy="true" allow-simultaneous-criterions-per-resource="true"
+        enabled="true" resource="RESOURCE">
 
         <criterion-list>
-            <criterion name="c1" active="true"/>
-            <criterion name="c2" active="true">
+            <criterion code="ct-4-c1" name="c1" active="true"/>
+            <criterion code="ct-4-c2" name="c2" active="true">
                 <children>
-                    <criterion name="c2-1" active="true">
+                    <criterion code="ct-4-c2-1" name="c2-1" active="true">
                         <children>
-                            <criterion name="c2-1-1" active="false"/>
-                            <criterion name="c2-1-2" active="true"/>
+                            <criterion code="ct-4-c2-1-1" name="c2-1-1" active="false"/>
+                            <criterion code="ct-4-c2-1-2" name="c2-1-2" active="true"/>
                         </children>
                     </criterion>
-                    <criterion name="c2-2" active="true"/>
+                    <criterion code="ct-4-c2-2" name="c2-2" active="true"/>
                 </children>
             </criterion>
         </criterion-list>
     </criterion-type>
 
     <!-- Repeated criterion type name (see above) -->
-    <criterion-type name=" CT-4 " description="ct-4 desc"
+    <criterion-type code="ct-4b" name=" CT-4 " description="ct-4 desc"
         allow-hierarchy="false"
         allow-simultaneous-criterions-per-resource="false" enabled="false"
         resource="WORKER"/>
 
     <!-- Repeated criterion type name (probably a criterion type with this name
          already exists in the database) -->
-    <criterion-type name="training" description="ct-4 desc"
+    <criterion-type code="ct-4c" name="training" description="ct-4 desc"
         allow-hierarchy="false"
         allow-simultaneous-criterions-per-resource="false" enabled="false"
         resource="WORKER"/>
 
     <!-- A non-active criterion has an active subcriterion -->
-    <criterion-type name="ct-5" description="ct-5 desc" allow-hierarchy="true"
-        allow-simultaneous-criterions-per-resource="true" enabled="true"
-        resource="RESOURCE">
+    <criterion-type code="ct-5" name="ct-5" description="ct-5 desc"
+        allow-hierarchy="true" allow-simultaneous-criterions-per-resource="true"
+        enabled="true" resource="RESOURCE">
 
         <criterion-list>
-            <criterion name="c1" active="true"/>
-            <criterion name="c2" active="false">
+            <criterion code="ct-5-c1" name="c1" active="true"/>
+            <criterion code="ct-5-c2" name="c2" active="false">
                 <children>
-                    <criterion name="c2-1" active="false"/>
-                    <criterion name="c2-2" active="false">
+                    <criterion code="ct-5-c2-1" name="c2-1" active="false"/>
+                    <criterion code="ct-5-c2-2" name="c2-2" active="false">
                         <children>
-                            <criterion name="c2-2-1" active="true"/>
+                            <criterion code="ct-5-c2-2-1" name="c2-2-1" active="true"/>
                         </children>
                     </criterion>
                 </children>
@@ -92,19 +92,19 @@
     </criterion-type>
 
     <!-- OK -->
-    <criterion-type name="ct-6" description="ct-6 desc"
+    <criterion-type code="ct-6" name="ct-6" description="ct-6 desc"
         allow-hierarchy="false"
         allow-simultaneous-criterions-per-resource="false" enabled="false"
         resource="WORKER"/>
 
     <!-- Resource type does not allow enabled criteria -->
-    <criterion-type name="ct-7" description="ct-5 desc" allow-hierarchy="true"
-        allow-simultaneous-criterions-per-resource="true" enabled="false"
-        resource="RESOURCE">
+    <criterion-type code="ct-7" name="ct-7" description="ct-5 desc"
+        allow-hierarchy="true" allow-simultaneous-criterions-per-resource="true"
+        enabled="false" resource="RESOURCE">
 
         <criterion-list>
-            <criterion name="c1" active="true"/>
-            <criterion name="c2" active="false"/>
+            <criterion code="ct-7-c1" name="c1" active="true"/>
+            <criterion code="ct-7-c2" name="c2" active="false"/>
         </criterion-list>
     </criterion-type>