LIST_VALUES

LIST_VALUES displays the list of values for the current item, as long as the input focus is in a text item that has an attached LOV. The list of values remains displayed until the operator dismisses the LOV or selects a value. By default, LIST_VALUES uses the NO_RESTRICT parameter. This parameter causes Oracle Forms not to use the automatic search and complete feature. If you use the RESTRICT parameter, Oracle Forms uses the automatic search and complete feature. 

Automatic Search and Complete Feature: 

With the automatic search and complete feature, an LOV evaluates a text item's current value as a search value. That is, if an operator presses [List] in a text item that has an LOV, Oracle Forms checks to see if the item contains a value. If the text item contains a value, Oracle Forms automatically uses that value as if the operator had entered the value into the LOV's search field and pressed [List] to narrow the list. If the item value would narrow the list to only one value, Oracle Forms does not display the LOV, but automatically reads the correct value into the field.

Usages of RESTRICT  kwyword:

Where list value has too many valus then it affects the performance of the application. At that time use RESTRICT.