Preserve original drop-down values when I update the drop-down value

My application holds a multi-tabbed form used to audit a case file. Each tab holds a small number of questions and available responses in drop-downs provided by reference selectors. So the response options are in associated entities (1-1, both and 1-*, default). I need to guarantee that the responses recorded in the form do not change over time. But I have realised that if I (or the administrator of the application) change the value of a response in an entity that provides the drop-down options then this changes the value stored in the form. What is the best practise to stop this happening? I know I can prevent deletion of a drop-down item by selecting the ’Delete ‘drop-down list’ object only if it is not associated with ‘Form’ object’ in the association properties. But what can I do to prevent or deter a drop-down value being changed and so changing all the historical forms that hold that value?
1 answers

Use the dropdowns to create flexibility, and then on an after commit, store the values you want "fixed" in the record.