ORC - Clarification on what triggers a change to Last Update Date

Summary:

As a pre-requisite of the Remove Person Information process, we are hoping to identify candidate data over X days old. This is to ensure that the client remains GDPR compliant.

We have found several variables within OTBI. One of these variables is 'Last Update Date'. We are looking for clarification on the events that would trigger an update to the 'Last Update Date' time stamp of a candidate.

The Taleo Implementation Guide is quite thorough and details a series of actions: Career Site Actions, Recruiting Centre Actions, CSP Actions, Candidate File Edits. Unfortunately, there is no similar information provided within the ORC Implementation Guide.