A source link can stop working even when the article citing it remains online. Pages move, organisations redesign their websites and content disappears, leaving readers unable to inspect the material behind a claim.
Perma.cc, developed by the Harvard Law School Library with partner institutions, addresses this problem by creating an archived record of a referenced page and a link to that capture.
The archive preserves access to a version of the material. That is valuable for showing what a source said, but it should not be confused with independent confirmation that the source’s statement was accurate.
Dates therefore matter twice: when the original material was published and when it was captured. A later archive may preserve a revised page rather than the version available when an earlier article was written.
Comparing versions can reveal a change, but the change still needs interpretation. A corrected number, a redesigned page and a deleted claim have different significance; an archive alone does not explain the reason.
Readers should also check whether the capture includes the material actually being cited. A page shell without the relevant document, video or dynamically loaded text may not preserve the evidence a link was intended to support.
Good citation practice connects the live source, a useful archived version and enough description to identify the document. That combination reduces dependence on a single address continuing to work indefinitely.
Archiving is consequently a way to protect the possibility of scrutiny. It keeps a record available for examination while leaving the central editorial question intact: what does this material establish, and what remains unproven?