Many prohibitions are not directly stated by the Society, however you as one of Jehovah's Witnesses know that shunning is being stressed at Assemblies and conventions.
Just as they say voting in a matter of conscience. They do not have the balls to put what they really believe on their web site or in print. Once again, however, what do you think would happen to an Elder or Pioneer who went down and cast a vote for the president?
Please read and learn from this site. There is a lot of good information.