A second citizenship leaves a more complete record than the holder usually appreciates. The acquisition itself sits in a government register, sometimes with a published gazette entry. The renewal of the document creates a further record. The use of the document at any border creates an entry in two countries' systems. None of this is hidden; most of it is not searched, but it is readable to those who do search.

Citizenship-by-investment programmes in particular produce a published trail. The investment threshold, the qualifying real estate, the financial contribution, the date of grant: in several jurisdictions, this is a matter of public record. A reader interested in a particular individual can establish, with patience, the route by which a second nationality was acquired and the approximate cost of it.

Even where the grant itself is not public, the document's use is. Airline manifests cross with immigration records. Frequent-flyer accounts hold travel histories that, taken together, can suggest a different identity than the one the principal presents in their primary life.

The work here is not to undo any of this; it is to know what the present record shows, to weigh the implications against the value the second citizenship provides, and to decide accordingly which exposures are tolerable and which are not.