diff --git a/SeedDMS_Core/Core/inc.ClassAttribute.php b/SeedDMS_Core/Core/inc.ClassAttribute.php
index 857b15ab4..2e9e6d11c 100644
--- a/SeedDMS_Core/Core/inc.ClassAttribute.php
+++ b/SeedDMS_Core/Core/inc.ClassAttribute.php
@@ -800,12 +800,52 @@ class SeedDMS_Core_AttributeDefinition { /* {{{ */
 			$sep = substr($value, 0, 1);
 			$vsep = $this->getValueSetSeparator();
 			if($sep == $vsep)
-				return(explode($sep, substr($value, 1)));
+				$values = explode($sep, substr($value, 1));
 			else
-				return(array($value));
+				$values = array($value);
 		} else {
-			return array($value);
+			$values = array($value);
 		}
+
+		switch((string) $this->getType()) {
+		case self::type_document:
+			foreach($values as $value) {
+				if($u = $this->_dms->getDocument((int) $value))
+					$tmp[] = $u->getName();
+				else
+					$tmp[] = '???';
+			}
+			$values = $tmp;	
+			break;
+		case self::type_folder:
+			foreach($values as $value) {
+				if($u = $this->_dms->getFolder((int) $value))
+					$tmp[] = $u->getName();
+				else
+					$tmp[] = '???';
+			}
+			$values = $tmp;	
+			break;
+		case self::type_user:
+			foreach($values as $value) {
+				if($u = $this->_dms->getUser((int) $value))
+					$tmp[] = $u->getLogin();
+				else
+					$tmp[] = '???';
+			}
+			$values = $tmp;	
+			break;
+		case self::type_group:
+			foreach($values as $value) {
+				if($u = $this->_dms->getGroup((int) $value))
+					$tmp[] = $u->getName();
+				else
+					$tmp[] = '???';
+			}
+			$values = $tmp;	
+			break;
+		}
+		return $values;
 	} /* }}} */
 
 	/**
@@ -1084,6 +1124,12 @@ class SeedDMS_Core_AttributeDefinition { /* {{{ */
 			}
 		}
 
+		/* Turn $attrvalue into an array of values. Checks if $attrvalue starts
+		 * with a separator char as set in the value set and uses it to explode
+		 * the $attrvalue. If the separator doesn't match or this attribute
+		 * definition doesn't have a value set, then just create a one element
+		 * array. if $attrvalue is empty, then create an empty array.
+		 */
 		if($this->getMultipleValues()) {
 			if(is_string($attrvalue)) {
 				$sep = $attrvalue[0];
@@ -1100,11 +1146,13 @@ class SeedDMS_Core_AttributeDefinition { /* {{{ */
 			$values = array();
 		}
 
+		/* Check if attribute value has at least the minimum number of values */
 		$this->_validation_error = 0;
 		if($this->getMinValues() > count($values)) {
 			$this->_validation_error = 1;
 			return false;
 		}
+		/* Check if attribute value has not more than maximum number of values */
 		if($this->getMaxValues() && $this->getMaxValues() < count($values)) {
 			$this->_validation_error = 2;
 			return false;
@@ -1163,6 +1211,42 @@ class SeedDMS_Core_AttributeDefinition { /* {{{ */
 			if(!$success)
 				$this->_validation_error = 4;
 			break;
+		case self::type_document:
+			foreach($values as $value) {
+				$success = true;
+				if(!$this->_dms->getDocument((int) $value))
+					$success = false;
+			}
+			if(!$success)
+				$this->_validation_error = 10;
+			break;
+		case self::type_folder:
+			foreach($values as $value) {
+				$success = true;
+				if(!$this->_dms->getFolder((int) $value))
+					$success = false;
+			}
+			if(!$success)
+				$this->_validation_error = 11;
+			break;
+		case self::type_user:
+			foreach($values as $value) {
+				$success = true;
+				if(!$this->_dms->getUser((int) $value))
+					$success = false;
+			}
+			if(!$success)
+				$this->_validation_error = 12;
+			break;
+		case self::type_group:
+			foreach($values as $value) {
+				$success = true;
+				if(!$this->_dms->getGroup((int) $value))
+					$success = false;
+			}
+			if(!$success)
+				$this->_validation_error = 13;
+			break;
 		}
 
 		if(!$success)