Greenhouse Permission Policies allows you to define certain settings that will apply to your entire Greenhouse account. These can be set in Configure > Permission Policies.
Users with Site Admin level permissions can configure Permission Policies, which are "umbrella" settings that apply to all users (and agencies) as defined below:
Here's a summary of what account-wide permissions can be configured in Greenhouse via the Permissions Policies:
This Permissions Policies Grid can also be downloaded as PDF here: