Facebook seem to be rolling out a threaded commenting system for the first time, based on a few reports of encounters with the system. Where it is used, Facebook users can hit “reply” on a comment in order to trigger a small comment reply form – which, when submitted, posts the new reply directly underneath the parent comment. This means comment sections are no longer exclusively chronological.

The implications of this new system (and whether it’s permanent) might be far-reaching in terms of impromptu group conversations, but it does benefit page owners, who can now more easily reply to specific fans. It certainly seems more apt for fan pages than user profiles, on which the system does not appear to have been rolled on. Even still, replies are hidden by default until users click a small icon representing the number of replies.

We’ll keep you updated if this feature changes in the future.

Update (3:03pm): Comments are shown in chronological order on Facebook’s mobile website, with no indication that a comment may have been originally posted as a reply.