Unten die ITTF-Regelung (seit 2008), gültig für Welttitelkämpfe. Wurde von der ETTU letztlich nicht übernommen. Für Olympia gelten andere Regeln (maximal 3 Jahre Wartezeit).
4.01.03.02 In addition to provisions of 3.8, players who have acquired a new nationality and wish to represent the association corresponding to the new nationality shall register with ITTF through this new Association.
4.01.03.03 Such player shall not represent the new association before
4.01.03.03.01
3 years after the date of registration, if the player is under the age of
15 when registered;
4.01.03.03.02
5 years after the date of registration, if the player is under the age of
18 but at least 15 years of age when registered;
4.01.03.03.03
7 years after the date of registration, if the player is under the age of
21 but at least 18 years of age when registered.
4.01.03.04 Players being
21 years of age or older will not be registered with the ITTF and will
not be eligible to represent a new association at World Championships.
http://ittf.com/ittf_handbook/ittf_hb.html