e) Death of the appellant (opponent) 

In T 1213/13, the board noted that the appellant, the only party to the proceedings adversely affected by the appealed decision, had died. The deadline set in the board's communication aiming to establish if there were any heirs had passed and the communication gone unanswered. It had therefore not been possible to identify any heirs (or legal representatives). Since the status of opponent could pass to any heirs, where an opponent was an appellant too, the heirs could pursue the appeal. However, they had to make themselves known and prove their status as such. The board declared the proceedings closed for want of an appellant to pursue them (see also T 74/00).