Final answer:
Expiry Alerts notify users when knowledge articles are approaching expiration, and they can be delivered through channels such as email, system notifications, or pop-ups.
Step-by-step explanation:
The type of notification that allows users to know when knowledge articles are going to expire is typically referred to as Expiry Alerts. These alerts are often set up within a Knowledge Management System (K_MS) or a content management system to notify content owners or stakeholders that content is approaching its expiration date. This feature ensures that outdated information is reviewed, updated, or archived to maintain the integrity of the knowledge base. Depending on the system, these alerts can be delivered through various channels, including but not limited to, email notifications, system notifications, or reminder pop-ups.