Abbreviations:

1. IUJP: Izin Usaha Jasa Pertambangan / Mining Services Business License
2. IUPK: Izin Usaha Pertambangan Khusus / Special Mining Business License
3. IUP BUMN: Izin Usaha Pertambangan Badan Usaha Milik Negara / State-Owned Enterprises Mining Business License
4. IUP OPK: Izin Usaha Pertambangan Operasi Produksi Khusus / Operation Production Special Mining Business License
5. KK: Kontrak Karya / Contract of Work
6. PKP2B: Perjanjian Karya Pengusahaan Pertambangan Batubara / Coal Mining Concession Agreement
7. SKT: Surat Keterangan Terdaftar / Registration Letter

Note:
SKT:  a certificate of registration for Non-Core Business Mining Company which conducts continuous activities at the mining site.

Source: Indonesia Ministry of Energy and Mineral Resources