One of the valuable features available to users that login to the Spirent CSC are subscriptions. Once you subscribe to content, you will get an email notification any time something you subscribe to is updated. Furthermore, the Spirent KB offers the chance to subscribe to as little or as much content as you need, and also the ability to choose entire categories of content all the way to the granularity of a single document.
Please note that subscriptions are permanent until you cancel them. To cancel a subscription, navigate to what you want to unsubscribe and click "Unsubscribe". The Subscription email will tell you where you subscribed so you can go and unsubscribe.