WASHINGTON - The Office of Corresponding Authors said Saturday that a paper must sit as corresponding author before it may file. Manuscripts that arrive only as PDFs are entered as notes. Under Circular CA-12, a clerk at the window seats the paper on the duty stool. The manuscript may issue only after the stool is date-stamped. "The paper is the clerk," said Ira Veld, counsel to the office. Labs that file PDFs without a seated author may store those runs in a side tray marked notes. At one journal window, a staffer not authorized to speak said two packets from the morning tray arrived bound and empty of a stool. Duty windows that issue papers begin the seated-author rule on 6 July. The office said the same stool will remain at the same window.