Most of those who applied at that time for admission were either high-ranking officials or academics. Historian Jonathan Spence, who retired just last year from Yale University, once recalled the multiple layers of red tape he had to get through before he was finally able to get in to see the collection in 1963 and finish his PhD dissertation.
當時申請入內觀賞者，多為政府高官或學者；去年才從美國耶魯大學退休的史學家史景遷便曾憶及，為了完成博士論文，他經過層層審核，才於 1963 年獲准進入「山洞」查閱清史檔案。