In the international standard classification, ppt involves: Telecommunication systems.
RU-GOST R, ppt
GOST 5.924-1971 Intermediate stations for train control tower and (railway) junction connection types PPT-66D and PPT-66P. Quality requirements of certified products
Professional Standard - Electron, ppt
SJ/T 31106-1994 Requirements of readiness and methods of inspection and assessment for PPT-10 diaphragm moulding machines