This standard describes the arrangement of the 44 basic printing keys on the typewriter and the characters@ uppercase and lowercase@ that appear on the keys. It also includes the two shift keys and the space bar. However@ the standard does not specify the physical characteristics and dimensions of the keys and keyboard. It relates to the keyboard arrangement only. Purpose. The purpose of this standard is to provide the greatest benefit to the user in the areas of operator training@ purchasing@ and interchangeability of machines and operators.