This article deals with the concepts of “Uniform Resource Indicator” (URI), “Uniform Resource Names” (URN), “Uniform Resource Characteristics” (URC) and “Uniform Resource Locator” (URL). Although it is not exhaustive because of the vastness of the topic, this article aims to offer a view on the topic to anyone who works and manages with remote electronic resources (RER) in their different aspects and different points of view. The analysed documents are: RFC Request for Comments (available in the IETF Internet Engineering Task Force’s website)and some drafts drawn up by the working groups within W3C The World Wide Web Consortium.