How to track the reason of a modification in a Rational Doors object?

All DOORS (traditional) users are entitled to use change management features of RTC, without additional license cost. Using the DOORS x RTC integration, it would be possible to customize a RCR (requirements change request) work item with a "modification reason" mandatory attribute thus forcing the user proposing a change to provide a reason. Other customizations would also be possible, using the flexibility of RTC, including custom work item states, team roles and workflows.

Hope this helps.