Normal courtesy is required in the contents of the messages. It is possible to complain about the contents of a message to the game master, who may take the adequate measures. Building Diplomacy on incitation to hate that leads to drawing people away from game/site will be grounds for expulsion from site (after warning).
This precious document lists the ambiguities to decide (in English). Diplomacy Adjudication Test CasesHere are all the home rules for adjudication on this site (in English). Home rulesHere are all the home rules for fixing orders of players so that they are accepted by adjudicator on this site (in English). Orders correctionThe test report of the adjudicator of the site (in English). Test report
Game rules Tournament regulations may amend these game rules.