Final answer:
Using 'Mark all as Not New' feature is a personal action that does not affect other users; it serves as a personal bookmark to manage one's notifications or messages.
Step-by-step explanation:
When you use the feature Mark all as Not New in an online platform, it typically resets your view of notifications or messages to show that you have reviewed all content. This action is a personal bookmark and will not change the status of these items for other users. For example, if you are part of a shared workspace or reading forum notifications, marking something as not new for yourself does not affect what appears as new or unread for other users. Each individual's view and marked notifications are unique to their account.