EDR stands for "Event Data/Detail Record". EDR records are used for systems that charge more than calls - content. e.g. buying ring tones. The generated CDR/EDR may not be in a form suitable for the particular rating system. In this case a piece of software, known as the mediation system, may be required to render the data into a form useful by the rating system. The mediation system is also useful for gathering data from various sources to aggregate into one record.