c) Review of first-instance discretionary decisions by the boards 

According to the settled jurisprudence of the boards of appeal, a board should only overrule the way in which a department of first instance has exercised its discretion if it concludes that the department has done so according to the wrong principles, or without taking into account the right principles, or in an unreasonable way (see e.g. T 879/18, citing T 491/09; T 222/16). For further details, see chapter V.A.3.4.1 below.