 According to R. A. Fletcher 

Up-to-date the Polycarpus certainly was.Gregory drew heavily upon the compilation of Anselm of Lucca and the "Collection in 74 Titles", the two most authoritative collections of the recent past, and he included pronouncements of Gregory VII, Urban II and Paschal II, and conciliar material from as late as Piacenza (1095).The scope of his book was comprehensive and its orderly arrangement made for ease of reference.