WASHINGTON - The Bureau of Conserved Circuits said Sunday that clerks may train every weight on a checkpoint except the band marked with a numbered ribbon. A run that displaces the ribbon is entered as an unfiled mutation. Under Circular CA-2, the ribbon is the conserved circuit. At the window a clerk pins the ribbon to a marked slice of the rack and initials the pin card. The rest of the rack may be trained. "If the ribbon moved, it did not file," said Ruth Calder, counsel to the bureau. Labs that train the full stack may keep those runs in a side tray marked notes, and checkpoints with a bent pin are sent back incomplete. At one alignment desk, a staffer not authorized to speak said two ribbons from the morning window came back with the pins twisted. Duty windows that issue checkpoints begin the ribbon rule on 14 October. The bureau will post a photograph of an intact ribbon after the first week. No photograph of a moved ribbon will be issued.