The relationship between the written description requirement and new matter is explained in MPEP 2163.06: "The written description requirement under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, is separate and distinct from the new matter prohibition of 35 U.S.C. 132(a)." This means that while both concepts are related to the content of a patent application, they serve different purposes and are evaluated separately. The written description requirement ensures that the inventor has possession of the claimed invention, while the new matter prohibition prevents the addition of undisclosed subject matter after the filing date. To learn more: written description new matter patent application 35 U.S.C. 112(a) 35 U.S.C. 132(a)