Domain Age
How old a domain is, from two sources that are allowed to disagree.
Two sources, kept apart. The registry says when the current registration began; the Internet Archive says when it first saw a page here. Where they disagree, that is the interesting part.
What it cannot tell you: who owned the name during an earlier life, or why a registration ended. A gap says there was one, not what happened in it. And a name with no archived pages leaves the registry date unchecked.