The definition for SVFR may be different in different countries, depending on the local aviation regulations.
The ICAO definition of Special VFR flight is a VFR flight cleared by air traffic control to operate within a control zone in meteorological conditions below visual meteorological conditions.
[2][3] SVFR at night requires an IFR-equipped aircraft and an IFR-rated pilot in command ("IFR" means Instrument flight rules).
[6] The aircraft need not necessarily be equipped for flight under IFR, and the aircraft must remain clear of clouds with the surface in sight, and maintain a certain flight visibility minimum (1,500 metres according to ICAO, one statute mile in the US, 1,500 m visibility, in sight of surface and clear of cloud in Europe).
Flight under a SVFR clearance at night requires the pilot to have an instrument rating and the aircraft must be IFR equipped.