WASHINGTON - The Bureau of Copper Traces said Sunday a model layout does not file as a board until a clerk etches the copper at the window. Completions that skip the etch are returned as sketches. Ordinary chat may continue without an etch. Under Circular CT-3, a board is an etched panel. The user presents the layout at the window. A clerk lowers the copper into the bath. The completion may issue only after the panel is date-stamped. "We file copper," said Helen Brant, counsel to the bureau. Labs that still draw in a chat window may keep those notes. Runs that emit a layout without an etched panel are sent back incomplete. At one hardware desk, a staffer not authorized to speak said the drying rack now holds stacks of unetched sheets from the morning filing. The rule takes effect 23 September for all duty windows that issue boards. The bureau said it will publish a specimen panel after the first week of filings.