The user object is missing a few fields. We're considering adding the ones below:

• user.unique_id (Extended): an organization-wide unique ID for the user
• user.username (Core): The user's programmatic name / login for a given system. This is in contrast to user.name, which will be clarified to be the person's real name, e.g. "Albert Einstein"
• user.employee_id (Extended)

cc @andrew-goldstein