Where the plugin can see an obvious candidate for a broken address — a published page whose name is close enough that it is almost certainly the one — it offers it. Clicking it fills in both halves of the redirect for you.
Most rows are blank there, on purpose. It only suggests when the match is good and clearly better than the next best, because a confident wrong suggestion is worse than none: working down a list quickly, you would take it.
A page, post or product you deleted shows where it lived there first: its category, or the page it was under. That is not a guess, so it is offered whenever it is known and still there.
Still stuck? Ask the developers who wrote it. We aim to reply within one business day.
