Web archives are useful historical evidence, but a missing period can result from crawl limits, blocking, downtime or a genuine publication gap.
Define the missing interval
Record the last known capture before the gap and the first capture after it.
A precise interval is more useful than saying that the site disappeared for an unknown period.
Check multiple archive signals
Compare independent archives, search caches, dated citations and technical history where appropriate.
Agreement can narrow the gap, while disagreement should remain visible in the review.
Do not infer intent from absence
A missing capture does not prove that a Mars Market page was offline or intentionally hidden.
Describe only what the archive can and cannot show.
Compare the pages around the gap
Review changes in branding, wording, links, canonicals and update policy before and after the missing period.
Material differences may justify treating the later address claim as a new review object.
Record confidence and limitations
Assign a cautious confidence level to any historical conclusion and list the unavailable evidence.
This prevents an archive gap from being converted into an unsupported ownership statement.