Watchers and notifications
When a split occurs, two things happen at the participant level: watchers are optionally migrated to the new part, and viewers currently on the previous part are optionally notified.
Watcher migration
Controlled by the Migrate watchers on split option (default on).
When migration is enabled, every user watching the previous part is subscribed to the new part with their existing email and alert preferences. Users who muted the previous part are not migrated; their mute does not carry forward to the new part either.
The migration runs as a job after the split completes; for chains with thousands of watchers it processes in batches and the chain row records watchers_migrated and watchers_migrated_retry_count so failures can be retried without duplicating subscriptions.
Disabling migration is appropriate for boards where the chain is intended to be a fresh start (for example a season-based megathread reset).
Active-viewer notifications
Controlled by the Notify active viewers on split option (default on).
When enabled, users who are currently viewing the previous part receive a soft in-page notification that a new part has started, with a link to it. The notification is delivered through the standard alert mechanism so users see it the next time they refresh.
This is helpful for live discussion threads where the conversation continues uninterrupted in the new part.
Continuation post and templates
Every new part starts with a system-generated continuation post. The body is built from the Continuation post template:
{final_post_quote}
Continued from {previous_part_link}.
Available tokens:
| Token | What it expands to |
|---|---|
{previous_part_link} | A BB-code link to the previous part. |
{previous_part_title} | The title of the previous part. |
{final_post_quote} | A BB-code quote of the previous part's final post. |
{final_post_author} | The author of the previous part's final post. |
Set the title pattern with the Title template option:
{title} (Part {part_number})
Available tokens:
| Token | What it expands to |
|---|---|
{title} | The base title (the original thread's title, with any existing part suffix stripped). |
{part_number} | The number of the new part (2 for the second part, 3 for the third, and so on). |
If the previous title already matches the template, the part number is incremented in place rather than appending a second suffix. So splitting Live Show — Tuesday (Part 2) yields Live Show — Tuesday (Part 3), not Live Show — Tuesday (Part 2) (Part 3).