I might suggest doing something like example.
*Year 1815 John Doe Immigration Record Ellis Island New York [ Link to source]
Just so its clear what that source represents. But getting back to the point a source is just a pointing out of where we got the information.
I however might mark it as uncertain.
Information from derivative sources, unless supported by other sources, should be considered uncertain and marked as such. However, since the community does not enforce a set standard of proof, this is a determination made by the editors of the profile — the Wiki Genealogists who are engaged in finding and evaluating sources of information.