Very interesting discussion... We are running version 12.7, and 'Root Cause' is on the Change Order screen. We haven't implemented Change Mgmt yet (still using a home grown system for that), but below are the Resolution Codes we have defined for Incidents and Requests.
We're soon going to be splitting out the combination code 'Started/Restarted/Rebooted/Recycled' into a few separate ones though, to assist with specifically tracking server reboots, which has recently become a big issue in our organization --
(Examples: 'Rebooted Server' 'Rebooted PC, Tablet, Phone, Other Device' 'Started/Restarted Application, Service, Session, Task, Process')
Tammy