Simplify the following text for a Grade 7 native English-speaking person.
Original: It safeguards all intellectual property rights relating to the DOI system , manages common operational features , and supports the development and promotion of the DOI system . The IDF ensures that any improvements made to the DOI system ( including creation , maintenance , registration , resolution and policymaking of DOI names ) are available to any DOI registrant .
Simplified: The DOI system has a DOI resolution system which is used to locate where the document is .