The bulk of the material was initially arranged (presumably by Dr Shapiro) in a flat structure with each file given a number from 1 to 305. In 1981 it was arranged and catalogued by staff at the AOF library in a 'Guide to the Material on ORT's History: An Annotated Catalogue' (d06a075). This later arrangement organised the files in a similar flat structure but under several thematic headings. The original file numbers were kept alongside new numbers which started from #1 under each new heading. The following headings were used: 

I ORT in Russia - Under the Tsars and Under the Soviets (1-81) 
II ORT Union in Eastern and Western Europe (1-73) 
III ORT in U.S.A. (1-31) 
IV ORT in Israel (1-12) 
V Asia, Africa, Latin America, Australia (1-21) 
VI General Sources (1-76) 
VII Reports [listing reports already included under other headings and in other files (1-58) 
VIII Technical Assistance [IC] (1-11) 

Following this cataloguing exercise, 9 more files were added to the series while it was still kept by American ORT. These later files included historical material which seemed relevant to this series (files 306-311) and later on, also correspondence with Leon Shapiro and his working papers and drafts for the History of ORT (files 312-314). The latter have been entered into a separate sub-series (WO/7/4/2/9). Files 306-311 were added to the existing appropriate series as these were originally created by the same entity that later added these files after the publication of the original finding aid.