Classified Catalogue Code lays down general principles about the choice of personal names as the basis of the heading. These principles are embodied in the Canons (general laws governing the treatment of a subject) formulated in the Code. For example, CCC states that "the safest course to determine the choice of the heading is to rely on the Canon of Ascertainability." Canon of Ascertainability states that the information found in the title page and its overflow pages of a document should be the guide for a cataloguer. Besides, guidance in the matter of choice of heading is also provided obliquely through the extended discussion on terminology and definitions. Rule FC31 is a basic rule. According to it, "Person as author, the responsibility for the thought and the expression constituting the work resting solely on his private capacity and not on the capacity body, nor on the capacity of that body". Thus, the question of responsibility, helps in deciding the choice of heading. It is here that the normative principles play an important role in helping to take a decision in the matter: By and large there is no difference between AACR and CCC with regard to the choice of personal names as the basis of the heading.