The Forward-Log holds units whose assessment is finished for this cycle. Open it from Assessment → Forward-Log.
How units get here
Automatically, a few days after their card reaches a completed stage on the Activity Board.
Straight away, with Forward log now on a completed card.
How they leave
Automatically, when their next cycle comes round (the due date less the lead time). They reappear in the Back-Log.
By hand, with Move to backlog, if something has changed and you need to look at a unit again before its next cycle.
What you can see
Click a unit to see the cycle's notes and history in the right-hand panel. Notes you add here are kept with the cycle they belong to.