(1) The World Science Fiction Society
Every current Worldcon member is automatically a member of WSFS and entitled to nominate and vote for the recipients of the Hugo Awards, to choose the locale of the Worldcon two years hence at site selection and, if attending, to participate in the WSFS Business Meeting, which governs the rules of the convention and the awards.
Years ago, Worldcons used to issue WSFS membership cards, but, sadly, that practice has died out.
WSFS also maintains a number of longstanding committees: the Mark Protection Committee (to which each Worldcon appoints members in addition to elected members), the Nitpicking and Flyspecking Committee, the Worldcon Runners Guide Editorial Committee, as well as the Hugo Eligibility Rest of the World Committee (HEROW). It also endorses the work of the Long List Committee.
WSFS is not to be confused with the historic, disastrous WSFS Inc.