The rules & regulations of the ITTF can be found in the ITTF Handbook of 2019. It can be viewed on the link below:

Handbook

Contact

International Table Tennis Federation
MSI, Avenue de Rhodanie 54B, 2
1007 Lausanne
SWITZERLAND (SUI)
Tel:+41 21 340 70 90
Fax:+41 21 340 70 99