18. No act, document or writing is binding upon the board, or may be attributed to it, unless it is signed by the president, a vice-president, the secretary or a commissioner or a personnel member designated by the board and only, in the last two cases, to the extent determined by the Government.
The Government may, on the conditions and for the documents it determines, allow the required signature to be affixed by means of an automatic device. It may also allow a facsimile of such signature to be engraved, lithographed or printed on such documents, subject to certification of the facsimile by the countersignature of a person authorized by the president.