Abstract :
A systematic scheme of classification of subjects in radio science and engineering is necessary in classifying references to current radio publications and also for classifying all sorts of other radio material, such as reports, reprints, drawings, books, apparatus, etc. In an effort to fill the need for a radio classification this extension of the Dewey decimal system was prepared. Since the publication of the first edition of this circular, in 1923, the subject classification it presents has been used extensively by many radio research workers and engineers as well as by the radio section of the Bureau of Standards. The present edition brings the classification up to date and makes a few changes which use has shown to be necessary.
