Under R. 113(2) EPC the signature can be replaced by a seal when a computer is used to produce the decision.
In T 225/96, the board noted that the forms accompanying the decisions are never signed, because they are computer-generated and therefore, under R. 70(2) EPC 1973 (R. 113(2) EPC), a seal may replace the signature.
In J 14/07 a communication produced using a computer in which a request for reimbursement of 50% of the examination fee had been refused was found to constitute a decision within the meaning of Art. 106(1) EPC 1973. Since it indicated the name of the formalities officer responsible and bore a seal, it complied with the requirements of the then applicable R. 70(2) EPC 1973 (now R. 113(2) EPC).