<span>The "Doomsday Book" was used by WIlliam the Conqueror to create a system of taxation in England. He wanted to determine how much each piece of property in England was worth, and how much every single person living in England was supposed to pay their taxes to the crown. Obviously, the name itself says that it was hated by the people, but the king wanted more money in his kingdom, which was why he resorted to using such a "book."</span>
I would say that the word "Testimonies" or "Testimonials" could fit in the blank. A testimonial is when someone discusses how your product, or argument is beneficial or correct.
