If you have an interest on a property and this interest is registered, it will have legal effects on third parties. The idea is the third party knew or should have known of a prior interest registered before the acquisition of his own interest. The government enhances certainty and security of land transactions by providing a registry system. The purpose of this registry system is to register anyone who has prescribed interests (such as mortgage) on a land so that third parties can inspect the registry and decide whether to make another transaction. There is of course a practical question of as to whether the current registry system provides such service to inquirers. Leaving this aside, another question is what if the interest is not registered because the law does not require such interest to be registered in the first place or because of other reasons. Consider the following: