I was just looking up the references for this thread in the ANO. Schedule 8 Part A Section 2 on the JAR PPL, refers to JAR FCL 1 para 1.175 which prohibits IFR flight without an IR unless (amongst other things) "national legislation requires flight in accordance with IFR under specified circumstances (e.g. at night), the holder of a pilot licence may fly under IFR, provided that pilot holds a qualification appropriate to the circumstances, airspace and flight conditions in which the flight is conducted".
So the privilege of daytime IFR in VMC in the open-FIR for JAR PPL holders is a side effect of having to use IFR at night? (As opposed to UK PPLs and NPPLs who get it directly.)
MC.