Currently if you format a line item as a Dependent list, the user gets a dropdown of list items that correspond to dependent criteria, same applies if they are typing the value. However it is possible to copy a name of a list item that is in the list (but does not suit dependent criteria) and paste it without getting an error.
Example - module has an input field City, dependent on Country line item. If the country is Germany they will not be able to select Paris in drop-down or type it, but they will be able to paste it into the input field.
A workaround is to use a subset as line item format, however we believe that user should get an error message when pasting a wrong list item in the dependent formatted line item.