A register of interests is an official record in which public officials disclose financial and personal interests that could potentially influence their decisions, such as property holdings, directorships, shareholdings, and significant gifts received while serving in public office over the course of their term, a point that deserves more attention than it gets.
These registers are usually required to be updated regularly, and many are made publicly accessible so that journalists, opposition politicians, and citizens can check whether a decision might be connected to an official's undisclosed personal interest at the relevant time it was actually made, however routine it may otherwise seem.
The register's real value lies less in any single entry and more in the pattern it allows others to see over time, making it considerably harder for a conflict of interest to remain hidden simply because no one thought to ask about it directly or closely enough.