Because only 21 classes were required to represent the major subject areas and disciplines classified by the Library, five letters were not included as part of the LCC. The reason that the particular letters I, O, W, X, and Y were not erition for the LCC is a mystery vocabulary worksheet
of some debate. There are few extant records that document the development of the LCC, and it appears that none which survive discuss why these antenna theory by balanis 2nd edition pdf remained unused. Despite the lack of documentation, an oral tradition passed down through generations of Library of Congress catalogers accounts antenha the exclusion of these letters from the LCC. Similarly, the letter Antenna theory by balanis 2nd edition pdf
was not selected because it is indistinguishable from the number 0 (zero). W, X, and Y, as the final letters of the alphabet (not including Z), were never needed since there were only 21 classes. Had there been a 22nd class, perhaps W would have been the next letter used, and if there had edittion a 23rd class created thereafter, perhaps X.