What I wonder is why the heck there is both a "Sola Scriputra caucus" and a "Protestant caucus". Given that the "sola scriputura" doctrine is only found in protestantism, isn't it redundant to have two caucuses? They will obviously have the same posters. Makes as much sense as having a "Catholic caucus" and then make a separate "Roman Papacy" caucus.
That definition is at odds with the majority of the Protestant world. The vast majority of Protestants claim it means that Scripture contains all that is necessary. Big difference.