G4IV

JM53, Houk88, and Keenan89 do not list a G4IV standard.

MK73 lists a G4III-IV standard (24 UMa = HR 3771 = HD 82210).

GrayNstars lists 24 UMa as their G4IV DSO standard. 

# Weak Standard
HD 82210 = HR 3771 = 24 UMa 
   G4III-IV: MK73
   G4IV: GrayNstars
   G9V_Fe-0.7: Gray03
   G0V(e): Li00(Halpha filled!)
   G5IV: Roman52(lines strong)
   G6IV: Abt86
   G2IV: Gyldenkerne55
   G4III-IV: Jaschek78(Slettebak55)
   G5III-IV: Keenan89
   G0: Cannon
   Jaschek64 lists 2 G4III-IV types, 4 G2IV types, and 4 G5IV types. 
   All over the place from G0 to G9, and V to III. 
   GrayNstars lists it as a G4IV standard, but Gray03 lists G9V_Fe-0.7.
   Probably not recommended for use as a standard.