Rights subject to registration pursuant to article 2521 are, if they have not been registered, unenforceable against third parties who, on the same immovable, have acquired, from the same author, competing rights subject to registration.
These rights are also unenforceable, if they have been registered, when the rights invoked by these third parties, were previously registered.
Third parties who were themselves responsible for having the competing rights published, or their universal successors in title, may not, however, avail themselves of this provision.