I have asked the list this several times and no one seems to know if there ever was such a rule. It is something that is written in MOST English language books on sumo (I have seen it in at least three books and on some web pages) and it sometimes differs whether it says Sandanme or Makushita. But since there have been rikishi at least since early 80s that never
FWIW,
~Doreen Simmons
<jz8d-smmn@asahi-net.or.jp>~
[EndPost by Doreen Simmons <jz8d-smmn@asahi-net.or.jp>]