This article is from the Table Tennis (Ping Pong) FAQ, by ttennis@bu.edu with numerous contributions by others.
6.1 In singles, the server shall first make a good service, the
receiver shall then make a good return and, thereafter, server and
receiver alternately shall each make a good return.
6.2 In Doubles, the server shall first make a good service, the
receiver shall then make a good return, the partner of the server
shall then make a good return, the partner of the receiver shall
then make a good return and, thereafter, each player alternately in
that sequence shall make a good return.
 
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