d) Period set for opponent to reply to patentee's response 

In T 138/08 the appellant (opponent) complained that two months and 21 days was not sufficient time to reply to the patentee's observations filed in response to the opposition. The board observed that the communication of the observations of the patentee had been made merely for information and the opposition division and had not raised any matter of substance in the communication. For that simple act a period of two months was considered sufficient. Therefore, the reimbursement of the appeal fee under R. 103(1)(a) EPC was not justified.