F2IV

JM53 lists bet Cas and ups UMa as F2IV standards.

MK73 lists 1 Mon (HR 2107) as the F2IV dagger standard. 

MorganAbt72 lists HR 1554 and HR 8765 as F2IV standards.

Cowley74 lists ups UMa, iot Leo, & HR 8765 as F2IV standards.

Garcia89 lists two F2IV standards: HD 40535 (1 Mon) and HD 84999 (ups
UMa), along with the F2III-IV standard HD 432 (bet Cas).

The MK78 atlas uses the F2III-IV standard Bet Cas, but no "IV" standard.  

GrayGarrison89 list 32 Tau as the low vsini F2IV standard, and do not
list a high vsini F2IV standard. GrayGarrison89 explicitly exclude
1 Mon as a standard star. 

There are no F2IV anchor points (Garrison94)

Houk88 does not list a F2IV standard. 

# Primary Standards
HD 24740 = HR 1218 = 32 Tau (J0356+2228)
  F2IV: Jaschek78(Cowley74),GrayGarrison89(low vsini stan),Gray89,Gray01(F2IVs)
  F0IV: Paunzen01
  F3V: Adams35
  F0: Cannon
  V=5.62, B-V=0.345+-0.004 (HIP). GrayGarrison89 primary "F2IV" standard.

# Secondary Standards
HD 40535 = 1 Mon
  F2IV: MK73,Jaschek78(Morgan72)
  F2III-IV: GrayGarrison89
  F2II: Bidelman51,Jaschek64(all)
  F0: Cannon
  Houk99 comments "HR 2107; 1 MON; V474 MON; ~SCT TYPE; 5.93-6.36V;
  0.13612600 DAY vSINi=25". In SMARTS list for 26/I and 47/I spectra. 

# Weak Standards
HD 432 = HR 21 = HIP 746 = Bet Cas
  F2IV: JM53,Jaschek64(most),Cowley67
  F2III-IV: Morgan72,MK78(stan)
  F2III: MK43,Gray89,GrayGarrison89,Gray01,Gray03(stan)
  F5: Cannon
  All published classifications since 1935 are "F2" subtype. Morgan
  flipflopped on luminosity class ("III" in MK43, "IV" in JM53,
  "III-IV" in MK78). Gray has consistently called it "F2III" in four
  publications, and considers it the "F2III" standard. I'm inclined
  to follow Gray and call it "F2III"

HD 84999 = ups UMa = HR 3888
  F2IV: JM53,Jaschek64(most),Peniche81
  F2III: MK43
  F0IV: Morgan72,GrayGarrison89
  F0: Cannon
  A9IV: Abt85
  Lots of disagreement in subtype and luminosity. 

HD 99028 = iot Leo
  F2IV: Slettebak55(SB),Jaschek64(most,SB),Stephenson69,Cowley74(stan)
  F2V: Roman49
  F4IV: Abt81
  F1IV+G3V: Edwards76 
  F3III: Levato78
  F3V: Abt09
  F5: Cannon
  F5IV: Gray03
  Only Cowley74 used this star as a standard. 
  1.5" pair. Negligible agreement among different investigators.
  Abt has been on three papers classifying this star - and all 
  three types were different (F4IV,F3V,F3III). 
  Quite possibly the worst choice of standard star -- ever. 

HD 217754 = HR 8765
  F2IV: Morgan72(stan),Cowley74(stan),Abt95
  F2Ib: Fehrenbach66(Kennedy83)
  F0IIp: Gray01(CaI 4227A strong)
  F0: Cannon
  Morgan72 and Cowley74 consider it a standard, but Gray01 disagrees 
  considerably with the type.