Standard Ventilation at "--" Degrees (Other than 32 Degrees)
VC
Vents Closed to Destination
VD40
Diagonal Ventilation at "--" Degrees (Other than 32 Degrees) - Open Vent Each End of Car
VDOI
Diagonal Vents on Irons
VO
Vents Open to Destination
VOI
Vents on Irons
VS
Standard Ventilation at 32 Degrees
VS10
Standard Ventilation - Substitute Carrier's Protective Service at First Terminal Train Yard where Heaters Are Available and Outside Temperature is 10 Degrees Above Zero or Lower (PPT #619 Rules 385 and 515)