Under Art. 11 RPBA 2020, a case is not to be remitted to the department whose decision was appealed, unless special reasons present themselves for doing so.
Whether "special reasons" present themselves is to be decided on a case-by-case basis. If all issues can be decided without undue burden, a board should normally not remit the case (see explanatory remarks on Art. 11 RPBA 2020 in Supplementary publication 2, OJ 2020).
In T 1531/16, the board held that, in view of the legislative intent reflected in the revised version of Art. 11, first sentence, RPBA 2020, a case should be remitted only if special reasons presented themselves for doing so, i.e. in exceptional cases (see also T 3247/19).
When deciding whether or not to remit a case, the boards have considered what special reasons within the meaning of Art. 11 RPBA 2020 presented themselves, e.g. whether there had been a comprehensive assessment of the case during the proceedings at first instance (see chapter V.A.9.3.2), whether the claims had been substantially amended (see point V.A.9.3.5), whether the search was complete (see chapter V.A.9.3.6) and whether the first-instance proceedings had been vitiated by fundamental deficiencies (see chapter V.A.9.4.). Other factors have also been taken into account, such as the need for procedural economy, the length of the proceedings, fairness of the proceedings and whether the parties requested remittal of the case. The weight given to each factor depended on the circumstances of the case in hand.