Bring an existing non-compliant catalog or published dataset into Portolan compliance without rebuilding it. Audit what is there, decide whether to patch or re-extract, repair metadata, styles and data, prove conformance, then republish and prune what went stale. Use when a catalog already exists and does not meet the spec, when a dataset was published before Portolan, or when someone says a catalog needs migrating, upgrading, or fixing.
