diff --git a/process/Attribute_lib/process.js b/process/Attribute_lib/process.js
index 65920bb205d841d8f486c4ceb39313c009bee5a1..92c097bcac9b56139c0c26dc1c0d5ad371c3021e 100644
--- a/process/Attribute_lib/process.js
+++ b/process/Attribute_lib/process.js
@@ -1227,8 +1227,8 @@ AttributeTypeUtil.getDatabaseField = function (pAttributeType)
  *                                              The attribute type (use the values <br>
  *                                              of the AttributeTypes object, e. g.<br>
  *                                              AttributeTypes.TEXT)<br>
- * @return {String[]}                           <p>
- *                                              The possible children types.<br>
+ * @return {String[]|null}                      <p>
+ *                                              The possible children types, can be null.<br>
  */
 AttributeTypeUtil.getPossibleChildren = function (pAttributeType)
 {
@@ -1244,8 +1244,8 @@ AttributeTypeUtil.getPossibleChildren = function (pAttributeType)
  *                                              The attribute type (use the values<br>
  *                                              of the AttributeTypes object, e. g.<br>
  *                                              AttributeTypes.TEXT)<br>
- * @return {String[]}                           <p>
- *                                              .<br>
+ * @return {Boolean}                            <p>
+ *                                              if the attribute can only be used once<br>
  */
 AttributeTypeUtil.isSingleSelection = function (pAttributeType)
 {
@@ -1269,6 +1269,16 @@ AttributeTypeUtil.getDropDownDefinitionTitle = function (pAttributeType)
     return type ? type.dropDownDefinitionTitle : "";
 }
 
+/**
+ * Returns a function to resolve the displayValue depending on the attribute type.
+ * 
+ * @param {String} pAttributeType               <p>
+ *                                              The attribute type (use the values<br>
+ *                                              of the AttributeTypes object, e. g.<br>
+ *                                              AttributeTypes.TEXT)<br>
+ * @return {Function}                           <p>
+ *                                              A function that resolves the displayValue or null if the type is invalid<br>
+ */
 AttributeTypeUtil.getDisplayValueSqlFn = function (pAttributeType)
 {
     var attributeType = AttributeTypes.get(pAttributeType);
@@ -1283,7 +1293,7 @@ AttributeTypeUtil.getDisplayValueSqlFn = function (pAttributeType)
  * 
  * @param {String} pAttributeType               <p>
  *                                              The attribute type which shall be comapred.
- * @return {String}                             <p>
+ * @return {Boolean}                            <p>
  *                                              Returns true, if the given attribute type is equal<br>
  *                                              with the attribute string "OBJECTSELECTION" and <br>
  *                                              false, if not.<br>