For the definition of a caucus see https://en.wikipedia.org/wiki/Caucus.
I found it interesting the hype over Hillary Clinton’s emails. I don’t think there was any real concern about the possibility of Clinton’s computer being hacked. This appeared to be a Republican party hack right before the Iowa caucus to make Clinton appear dishonest and untrustworthy. Colin Powell has said he used a personal email account during his tenure as Secretary of State. http://www.politico.com/story/2015/03/colin-powell-personal-email-secretary-of-state-115707. And let’s not forget John Brennan, director of the CIA whose AOL account was hacked. http://fortune.com/2015/10/22/cia-aol-email-hack/
From what I understand, the State Department has clarified its wording. You can probably find it in this 63-page document. If you’re like me, after page one, the hell with this.