Organisasi Amatir Radio Indonesia
The Organisasi Amatir Radio Indonesia (ORARI) (in English, Amateur Radio Organization of Indonesia) is a national non-profit organization for amateur radio enthusiasts in Indonesia. According to a 2000 census compiled by the International Amateur Radio Union, Indonesia has the thirteenth-largest population of amateur radio operators in the world. A key membership benefit of the ORARI is a QSL bureau for those Indonesian amateur radio operators in regular communications with other amateur radio operators in foreign countries. The ORARI represents the interests of Indonesian amateur radio operators before Indonesian and international regulatory authorities. ORARI is  the national member society representing Indonesia in the International Amateur Radio Union. Call areas. ORARI divides amateur radio privilege into four classes. The starting level is Pemula (Novice) with prefix YH The General Class is Siaga (Alert) whose prefix is YD/YG. The advanced level is Penggalang (Supporter) with the prefix of YC/YF. The highest level is Penegak (Extra Class) with the prefix of YB/YE. As a vast archipelago, Indonesia is divided into several call areas;