Definitions of device types, such as Open Market and Unlocked devices, are not consistently defined around the world. TS.59 formalises the requirements that underpin such terminology so that all parties can work from a common baseline.

TS.59 is also intended to serve as a reference document for other GSMA PRDs. It also details the requirements that underpin certain device type definitions and is applicable where devices and networks have obtained GSMA certification of compliance with IR.25 (VoLTE Roaming Testing).