diff --git a/docs/garbage-collector.md b/docs/garbage-collector.md
new file mode 100644
index 000000000..14c92a966
--- /dev/null
+++ b/docs/garbage-collector.md
@@ -0,0 +1,4 @@
+
+
+* post_meta of deleted fields
+* post_meta of deleted instaces of a multiple compound Field. post_meta of a field that is child of a compound field, but which the ID does not appear in any array of a compound field meta_value
\ No newline at end of file
diff --git a/src/classes/entities/class-tainacan-item-metadata-entity.php b/src/classes/entities/class-tainacan-item-metadata-entity.php
index e88244859..7d4294edc 100644
--- a/src/classes/entities/class-tainacan-item-metadata-entity.php
+++ b/src/classes/entities/class-tainacan-item-metadata-entity.php
@@ -16,10 +16,26 @@ class Item_Metadata_Entity extends Entity {
 	 */
 	protected $repository = 'Item_Metadata';
 	
-    function __construct(Item $item, Field $field) {
+	/**
+	 * 
+	 * @param Item   $item    Item Entity
+	 * @param Field  $field   Field Entity
+	 * @param int $meta_id ID for a specific meta row 
+	 */
+    function __construct(Item $item, Field $field, $meta_id = null, $parent_meta_id = null) {
         
         $this->set_item($item);
         $this->set_field($field);
+		
+		if (!is_null($meta_id) && is_int($meta_id)) {
+			$this->set_meta_id($meta_id);
+		}
+		
+		if (!is_null($parent_meta_id) && is_int($parent_meta_id)) {
+			$this->set_parent_meta_id($parent_meta_id);
+		}
+		
+		
     }
 
 	public function  __toString(){
@@ -63,6 +79,39 @@ class Item_Metadata_Entity extends Entity {
     function set_field(Field $field) {
         $this->field = $field;
     }
+	
+	/**
+	 * Set the specific meta ID for this metadata.
+	 *
+	 * When this value is set, get_value() will use it to fetch the value from 
+	 * the post_meta table, instead of considering the item and field IDs
+	 * 
+	 * @param int $meta_id the ID of a specifica post_meta row
+	 */
+	function set_meta_id($meta_id) {
+		if (is_int($meta_id)) {
+			$this->meta_id = $meta_id;
+			return true;
+			// TODO: Should we check here to see if this meta_id is really from this field and item?
+		}
+		return false;
+	}
+	
+	/**
+	 * Set parent_meta_id. Used when a item_metadata is inside a compound Field 
+	 *
+	 * When you have a multiple compound field, this indicates of which instace of the value this item_metadata is attached to
+	 * 
+	 * @param [type] $parent_meta_id [description]
+	 */
+	function set_parent_meta_id($parent_meta_id) {
+		if (is_int($parent_meta_id)) {
+			$this->parent_meta_id = $parent_meta_id;
+			return true;
+			// TODO: Should we check here to see if this meta_id is really from this field and item?
+		}
+		return false;
+	}
     
     /**
      * Return the item
@@ -81,6 +130,24 @@ class Item_Metadata_Entity extends Entity {
     function get_field() {
         return $this->field;
     }
+	
+	/**
+     * Return the meta_id
+     *
+     * @return Field
+     */
+    function get_meta_id() {
+        return isset($this->meta_id) ? $this->meta_id : null;
+    }
+	
+	/**
+     * Return the meta_id
+     *
+     * @return Field
+     */
+    function get_parent_meta_id() {
+        return isset($this->parent_meta_id) ? $this->parent_meta_id : 0;
+    }
     
     /**
      * Return the field value
@@ -157,10 +224,6 @@ class Item_Metadata_Entity extends Entity {
                 foreach($value as $val) {
                     if (!empty($val))
                         $one_filled = true;
-                    
-                    // TODO: call fieldtype validation
-                    // if (invalid) $valid = false;
-                    
                 }
                 
                 if ($this->is_required() && !$one_filled) {
diff --git a/src/classes/entities/class-tainacan-item.php b/src/classes/entities/class-tainacan-item.php
index d47c60853..32d8b45c6 100644
--- a/src/classes/entities/class-tainacan-item.php
+++ b/src/classes/entities/class-tainacan-item.php
@@ -309,6 +309,11 @@ class Item extends Entity {
 					if ( $pos !== false ) {
 						continue;
 					}
+					
+					// skip validation for Compound Fields
+					if ( $itemMetadata->get_field()->get_field_type() == 'Tainacan\Field_Types\Compound' ) {
+						continue;
+					}
 
 					if ( ! $itemMetadata->validate() ) {
 						$errors = $itemMetadata->get_errors();
diff --git a/src/classes/field-types/compound/class-tainacan-compound.php b/src/classes/field-types/compound/class-tainacan-compound.php
new file mode 100644
index 000000000..4f3735bf0
--- /dev/null
+++ b/src/classes/field-types/compound/class-tainacan-compound.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace Tainacan\Field_Types;
+
+defined( 'ABSPATH' ) or die( 'No script kiddies please!' );
+
+/**
+ * Class TainacanFieldType
+ */
+class Compound extends Field_Type {
+
+    function __construct(){
+        // call field type constructor
+        parent::__construct();
+        $this->set_primitive_type('compound');
+        $this->set_component('tainacan-compound');
+    }
+
+    /**
+     * @param $itemMetadata \Tainacan\Entities\Item_Metadata_Entity The instace of the entity itemMetadata
+     * @return string
+     */
+
+    public function render( $itemMetadata ){
+        return '<tainacan-text 
+                               id="tainacan-text-' . $itemMetadata->get_item()->WP_Post->post_name . '"
+                               field_id ="'.$itemMetadata->get_field()->get_id().'" 
+                               item_id="'.$itemMetadata->get_item()->get_id().'"    
+                               value=\''.json_encode( $itemMetadata->get_value() ).'\'  
+                               name="'.$itemMetadata->get_field()->get_name().'"></tainacan-text>';
+    }
+
+    /**
+     * generate the fields for this field type
+     */
+    public function form(){
+
+    }
+
+    
+}
\ No newline at end of file
diff --git a/src/classes/repositories/class-tainacan-fields.php b/src/classes/repositories/class-tainacan-fields.php
index 38b227339..978b91e82 100644
--- a/src/classes/repositories/class-tainacan-fields.php
+++ b/src/classes/repositories/class-tainacan-fields.php
@@ -68,7 +68,7 @@ class Fields extends Repository {
                 //'validation' => v::numeric(),
             ],
             'parent'         => [
-                'map'        => 'parent',
+                'map'        => 'post_parent',
                 'title'      => __('Parent', 'tainacan'),
                 'type'       => 'integer',
                 'description'=> __('Parent field', 'tainacan'),
@@ -252,7 +252,10 @@ class Fields extends Repository {
      * @param $class_name string | object The class name or the instance
      */
     public function register_field_type( $class_name ){
-        if( is_object( $class_name ) ){
+        
+		// TODO: we shoud not allow registration of field types of retricted core field types (e.g. compound, term) by plugins
+		
+		if( is_object( $class_name ) ){
             $class_name = get_class( $class_name );
         }
 
diff --git a/src/classes/repositories/class-tainacan-item-metadata.php b/src/classes/repositories/class-tainacan-item-metadata.php
index 28dc1bdf7..0b48db004 100644
--- a/src/classes/repositories/class-tainacan-item-metadata.php
+++ b/src/classes/repositories/class-tainacan-item-metadata.php
@@ -35,9 +35,30 @@ class Item_Metadata extends Repository {
 			$this->save_core_field_value($item_metadata);
 		} elseif ($field_type->get_primitive_type() == 'term') {
 			$this->save_terms_field_value($item_metadata);
+		} elseif ($field_type->get_primitive_type() == 'compound') {
+			// do nothing. Compound values are updated when its child fields are updated
+			return $item_metadata;
 		} else {
 			if ($unique) {
-	            update_post_meta($item_metadata->item->get_id(), $item_metadata->field->get_id(), wp_slash( $item_metadata->get_value() ) );
+				
+				if (is_int($item_metadata->get_meta_id())) {
+					update_metadata_by_mid( 'post', $item_metadata->get_meta_id(), wp_slash( $item_metadata->get_value() ) );
+				} else {
+					// update_post_meta returns meta ID on addition and true on update
+					$added_meta_id = update_post_meta($item_metadata->item->get_id(), $item_metadata->field->get_id(), wp_slash( $item_metadata->get_value() ) );
+				}
+				
+				// handle fields inside Compound fields when adding a new meta value
+				
+				//var_dump($item_metadata->get_field()->get_parent());
+				//var_dump($item_metadata->get_parent_meta_id());
+				//var_dump($item_metadata->get_value());
+				//die;
+				
+				if ( ( $item_metadata->get_field()->get_parent() > 0 || $item_metadata->get_parent_meta_id() > 0 ) && is_int($added_meta_id)) {
+					$added_compound = $this->add_compound_value($item_metadata, $added_meta_id);
+				}
+				
 	        } else {
 	            delete_post_meta($item_metadata->item->get_id(), $item_metadata->field->get_id());
 	            
@@ -56,7 +77,18 @@ class Item_Metadata extends Repository {
         do_action('tainacan-insert', $item_metadata);
         do_action('tainacan-insert-Item_Metadata_Entity', $item_metadata);
 
-        return new Entities\Item_Metadata_Entity($item_metadata->get_item(), $item_metadata->get_field());
+        $new_entity = new Entities\Item_Metadata_Entity($item_metadata->get_item(), $item_metadata->get_field());
+		
+		if (isset($added_compound) && is_int($added_compound)) {
+			$new_entity->set_parent_meta_id($added_compound);
+		}
+		
+		if (isset($added_meta_id) && is_int($added_meta_id)) {
+			$new_entity->set_meta_id($added_meta_id);
+		}
+		
+		return $new_entity;
+		
     }
 
 	/**
@@ -94,6 +126,34 @@ class Item_Metadata extends Repository {
 
 		}
 	}
+	
+	/**
+	 * 
+	 * @return null|ind the meta id of the created compound metadata
+	 */
+	public function add_compound_value(Entities\Item_Metadata_Entity $item_metadata, $meta_id) {
+		
+		$current_value = get_metadata_by_mid( 'post', $item_metadata->get_parent_meta_id() );
+		
+		if (is_object($current_value))
+		 	$current_value = $current_value->meta_value;
+			
+		//var_dump($current_value); die;
+		if ( !is_array($current_value) )
+			$current_value = [];
+		
+		if ( !in_array( $meta_id, $current_value ) ) {
+			$current_value[] = $meta_id;
+		}
+		
+		if ( $item_metadata->get_parent_meta_id() > 0 ) {
+			update_metadata_by_mid( 'post', $item_metadata->get_parent_meta_id(), $current_value );
+		} elseif ( $item_metadata->get_field()->get_parent() > 0 ) {
+			return add_post_meta( $item_metadata->get_item()->get_id(), $item_metadata->get_field()->get_parent(), $current_value );
+		}
+		
+		
+	}
 
 	/**
 	 * Fetch Item Field objects related to an Item
@@ -164,12 +224,73 @@ class Item_Metadata extends Repository {
 				$terms = reset($terms);
 			
 			return $terms;
+		
+		} elseif ($field_type->get_primitive_type() == 'compound') {
+			
+			global $wpdb;
+			$rows = $wpdb->get_results( 
+				$wpdb->prepare("SELECT * FROM $wpdb->postmeta WHERE post_id = %d AND meta_key = %s", $item_metadata->get_item()->get_id(), $item_metadata->field->get_id()), 
+				ARRAY_A );
+			
+			$return_value = [];
+			
+			if (is_array($rows)) {
+				
+				foreach ($rows as $row) {
+					$value = $this->extract_compound_value(maybe_unserialize($row['meta_value']), $item_metadata->get_item(), $row['meta_id']);
+					if ( $unique ) {
+						$return_value = $value;
+						break;
+					} else {
+						$return_value[] = $value;
+					}
+				}
+				
+			}
+			
+			return $return_value; 
 			
         } else {
-            return get_post_meta($item_metadata->item->get_id(), $item_metadata->field->get_id(), $unique);
+            if (is_int($item_metadata->get_meta_id())) {
+				$value = get_metadata_by_mid( 'post', $item_metadata->get_meta_id() );
+				if ( is_object($value) && isset( $value->meta_value) ) {
+					return $value->meta_value;
+				}
+			} else {
+				return get_post_meta($item_metadata->item->get_id(), $item_metadata->field->get_id(), $unique);
+			}
+			
         }
         
     }
+	
+	/**
+	 * Transforms the array saved as meta_value with the IDs of post_meta saved as a value for compound fields
+	 * and converts it into an array of Item Metadatada Entitites
+	 *
+	 * @param array $ids The array of post_meta ids
+	 * @param Entities\Item $item The item this post_meta is related to
+	 * @param int $compund_meta_id the meta_id of the parent compound metadata
+	 * @return array An array of Item_Metadata_Entity objects
+	 */
+	private function extract_compound_value(array $ids, Entities\Item $item, $compund_meta_id) {
+		
+		$return_value = [];
+		
+		if (is_array($ids)) { 
+			foreach ($ids as $id) {
+				$post_meta_object = get_metadata_by_mid( 'post', $id );
+				if ( is_object($post_meta_object) ) {
+					$field = new Entities\Field($post_meta_object->meta_key);
+					$return_value[] = new Entities\Item_Metadata_Entity( $item, $field, $id, $compund_meta_id );
+				}
+				
+			}
+		}
+		
+		return $return_value;
+		
+	}
 
     public function register_post_type() { }
     
diff --git a/src/classes/tainacan-creator.php b/src/classes/tainacan-creator.php
index a49f247dc..e517421ba 100644
--- a/src/classes/tainacan-creator.php
+++ b/src/classes/tainacan-creator.php
@@ -88,6 +88,7 @@ $Tainacan_Fields->register_field_type('Tainacan\Field_Types\Numeric');
 $Tainacan_Fields->register_field_type('Tainacan\Field_Types\Selectbox');
 $Tainacan_Fields->register_field_type('Tainacan\Field_Types\Relationship');
 $Tainacan_Fields->register_field_type('Tainacan\Field_Types\Category');
+$Tainacan_Fields->register_field_type('Tainacan\Field_Types\Compound');
 
 $Tainacan_Filters = \Tainacan\Repositories\Filters::getInstance();
 
diff --git a/tests/test-compound-field-types.php b/tests/test-compound-field-types.php
new file mode 100644
index 000000000..c9f07d1f8
--- /dev/null
+++ b/tests/test-compound-field-types.php
@@ -0,0 +1,128 @@
+<?php
+
+namespace Tainacan\Tests;
+
+/**
+ * Class TestCollections
+ *
+ * @package Test_Tainacan
+ */
+
+use Tainacan\Entities;
+
+/**
+ * Sample test case.
+ */
+class CompoundFieldTypes extends TAINACAN_UnitTestCase {
+
+	
+    function test_compound_field_types() {
+
+        $Tainacan_Fields = \Tainacan\Repositories\Fields::getInstance();
+        $Tainacan_Item_Metadata = \Tainacan\Repositories\Item_Metadata::getInstance();
+        $Tainacan_Items = \Tainacan\Repositories\Items::getInstance();
+        
+        $collection = $this->tainacan_entity_factory->create_entity(
+			'collection',
+			array(
+				'name'   => 'test',
+			),
+			true
+		);
+		
+        $field = $this->tainacan_entity_factory->create_entity(
+        	'field',
+	        array(
+	        	'name' => 'meta',
+		        'description' => 'description',
+		        'collection' => $collection,
+		        'field_type' => 'Tainacan\Field_Types\Compound',
+				'status'	 => 'publish',
+	        ),
+	        true
+        );
+        
+        $field_child1 = $this->tainacan_entity_factory->create_entity(
+        	'field',
+	        array(
+	        	'name' => 'meta2',
+		        'description' => 'description',
+		        'collection' => $collection,
+		        'field_type' => 'Tainacan\Field_Types\Text',
+				'status'	 => 'publish',
+				'parent' 	 => $field->get_id(),
+	        ),
+	        true
+        );
+		
+		$field_child2 = $this->tainacan_entity_factory->create_entity(
+        	'field',
+	        array(
+	        	'name' => 'meta3',
+		        'description' => 'description',
+		        'collection' => $collection,
+		        'field_type' => 'Tainacan\Field_Types\Text',
+				'status'	 => 'publish',
+				'parent' 	 => $field->get_id(),
+	        ),
+	        true
+        );
+        
+        
+        $i = $this->tainacan_entity_factory->create_entity(
+			'item',
+			array(
+				'title'         => 'item test',
+				'description'   => 'adasdasdsa',
+				'collection'    => $collection,
+				'status'		   => 'publish',
+			),
+			true
+		);
+	   
+		$item_metadata1 = new \Tainacan\Entities\Item_Metadata_Entity($i, $field_child1);
+		$item_metadata1->set_value('Red');
+		
+		$item_metadata1->validate();
+
+		$item_metadata1 = $Tainacan_Item_Metadata->insert($item_metadata1);
+		
+		$item_metadata = new \Tainacan\Entities\Item_Metadata_Entity($i, $field_child2, null, $item_metadata1->get_parent_meta_id());
+		$item_metadata->set_value('Blue');
+		
+		$item_metadata->validate();
+
+		$item_metadata = $Tainacan_Item_Metadata->insert($item_metadata);
+		
+		$compoundItem = new \Tainacan\Entities\Item_Metadata_Entity($i, $field);
+		
+		global $wpdb;
+		
+		var_dump($wpdb->get_results("SELECT * FROM $wpdb->postmeta WHERE post_id = {$i->get_id()}"));
+		//var_dump($wpdb->get_results("SELECT * FROM $wpdb->posts WHERE parent = {$field->get_id()}"));
+		
+		$compoundValue = $compoundItem->get_value();
+		
+		$this->assertTrue( is_array($compoundValue), 'value of a compound should return array' );
+		$this->assertEquals( 2, sizeof($compoundValue), 'value should have 2 item metadata' );
+		
+		$this->assertTrue( $compoundValue[0] instanceof \Tainacan\Entities\Item_Metadata_Entity , 'First element of value should be an item metadata entity' );
+		$this->assertTrue( $compoundValue[1] instanceof \Tainacan\Entities\Item_Metadata_Entity , 'Second element of value should be an item metadata entity' );
+		
+		//var_dump($compoundValue);
+		$metas = [];
+		foreach ($compoundValue as $val) {
+			$metas[$val->get_field()->get_id()] = $val->get_value();
+		}
+		
+		$this->assertEquals( 'Red', $metas[$field_child1->get_id()] , 'First element of value should have "Red" value' );
+		$this->assertEquals( 'Blue', $metas[$field_child2->get_id()] , 'Second element of value should have "Blue" value' );
+		
+		//var_dump($compoundValue[0]->get_field()->get_id());
+		//var_dump($field_child2->get_id());
+		//var_dump($field_child1->get_id());
+		//var_dump($field->get_id());
+		
+    }
+	
+}
\ No newline at end of file