6 6 6 ## rrs-isotopism class reps of symmetric Latin squares abcdef badcfe cdefab dcfeba efabcd febadc abcdef badcfe cdefab dcfeba efabdc febacd bafcde abcdef fcdeba cdefab debafc efabcd dcefba cfdeab edbafc feabcd bafcde abcdef abcdef bafecd cfabde debafc ecdfab fdecba abcdef bafecd cfabde debafc ecdfba fdecab Found 6 different among 30 A complete list.