The crew feature provides instant chat messaging and in-app notificaitons to Nuke users.
With the chat it is possible to send instant messages to your fellow colleagues. Online users are classified in the UI based on how they are related to your scene.
The in app-notifications tab gives a notifications feed for the items in your scene. Task assignments, status changes, new versions and changes to frame start / end will show up in the feed.
As of now the chat messages are not encrypted and anyone with a valid ftrack API KEY can listen in on any chat.