I am registered in California with No Party Preference (NPP). When I registered, Republican was clearly listed among the party choices. Last month I got a notice from my county registrar explaining that I could request a no-party ballot at election time, or I would have a choice of voting in the primaries of one of three parties (Democrat, American Independent and Libertarian) whose party rules allow non-party members to participate in their primaries. According to party rules, if I want to vote in another party's primary, such as Republican or Green, I would need to re-register as a member of that party. A little complicated but it was clearly explained.