PoundWeight is a unit of force.
PrintersPoint is a unit of length.
PSI
						 
						(Units Package Symbol) PSI is a unit of pressure.
Quart
						 
						(Units Package Symbol) Quart is a unit of volume.
Quintal is a unit of mass.
Rad
						 
						(Units Package Symbol) Rad is a unit of absorbed dose of radiation.
Rankine is a unit of temperature.
RegisterTon is a unit of volume.
Reyn
						 
						(Units Package Symbol) Reyn is a unit of absolute viscosity.
Rhes
						 
						(Units Package Symbol) Rhes is a unit of viscosity.