Because the method of Gödel numbering was novel, and to avoid any ambiguity, Gödel presented a list of 45 explicit formal definitions of primitive recursive functions and relations used to manipulate and test Gödel numbers.
In footnote 48a, Gödel stated that a planned second part of the paper would establish a link between consistency proofs and type theory, but Gödel did not publish a second part of the paper before his death.