Since rules and laws governing IP vary by country, the best advice is to consult with an attorney in your country who specializes in that field.
Intellectual property carries many of the same properties as real property has in Western countries, but there are distinct differences as well. Most important, since IP is a relatively new area that has been greatly impacted by computers and the Internet, while real property has not been so impacted, the laws and interpretations governing IP are still evolving. That is why you need to consult someone current in the field.
As an example of the complexity of the law, review this recent decision by the SCOTUS: **broken link removed**
John