NRSC-4-A (the U.S. RBDS Standard) includes an "open data application" feature. This feature enables proprietary (or non-proprietary) communications systems to be implemented via the RDS data stream.
The data in these systems is transmitted in one or more of the blocks in the RDS data stream. A special code, called the Application Identification (AID) Code is transmitted in Group Type 0A to identify the particular application being transmitted. Each different open data application must have its own AID code.
To obtain an AID code in the United States the company or individual requesting it must fill out the form found in Appendix L of NRSC-4-A and send the completed form along with a check for $495 to:RDS Registrations Office
Upon receipt of the completed form and the processing fee the RDS Registrations Office will issue an AID code to the applicant.
To help make obtaining an AID code as simple as possible, the NRSC and the EBU have coordinated their efforts to assign these codes. Codes that are assigned by the NRSC in the US can also be used in Europe, and codes that are assigned by the RDS Forum in Europe can also be used in the US. There are two separate registrations offices in order to allow applicants to obtain AID codes from an office that is in their same general region of the world. European companies or individuals who want to obtain an AID code may visit the European RDS Forum Web Site.