Make SOP Analysis Codes mandatory for Sales Returns only

A requirement has been highlighted for one of our customers to be able to create an Analysis Code to use in SOP that would be mandatory but for Sales Returns only. This would allow the customer to analyse their Sales Returns in more detail, such as the reason for return e.g. manufacturer fault, damaged by customer etc. However, the current functionality only allows for the analysis code to be mandatory for SOP and not Orders or Returns specifically.As the Analysis Code is not mandatory,some users may forget to fill in the analysis code detail on the Sales Return.