A group of disaffected priests from the Society of Saint Pius the Tenth (SSPX) that left and formed their own organization when the SSPX began dialogue with the Holy See concerning reconcilliation. The SSPV advocate Sedevacantism, which means they believe that the Papal Office is vacant, and the current Pope is an antipope. Most members will contest the Papal reigns of Blessed John XXIII, Paul VI, John Paul, Blessed John Paul II, and Benedict XVI, although some do accept the legitimacy of Blessed John XXIII's reign. The SSPV do not hold the Second Vatican Council (Vatican II) as valid and binding on Catholics because they believe that it's decrees contradict the traditional Catholic faith and are "heresy." The SSPV rejects the Ordinary form liturgy of Paul VI, and celebrates all the Sacraments (Especially the Eucharist) according to the Traditional Latin Missal. The SSPV, like many other Sedevacantist groups claim that they are the true Catholic Church, and the Modern Church is Heretical, sometimes citing the apocalyptic warning given by Our Lady of Salette.
In short a marginalized group, excommunicate from the Catholic Church proper, who make up a small minority of the world's traditionalists.
Bill said he believes in sedevacantism and has started attending that "Society of Saint Pius the Fifth (SSPV)" chapel on Market Street.