The DOI is persistent, meaning that the identification of a digital object does not change even if ownership of or rights in the entity are transferred. It is also actionable, meaning that clicking on it in a Web browser display will redirect the user to the content. The DOI is also interoperable, designed to function in past, present, and future digital technologies. The registration and resolver system for the DOI is run by the International DOI Foundation (IDF). CrossRef is a collaborative citation linking service that uses the DOI. Click here to learn more about the DOI.