[Q^2 definition in hard scattering/renormalization scale]
MSTP(32)=8(default) : pt^2+(P1^2+P2^2+m3^2+m4^2)/2

[ISR, factorization scale]
Space-like p2-E2>0
MSTP(61) = 0(off)/1(on)/2(on,default)
PARP(67) = 1.(default); Qfac2=Q2*PARP(67)

[FSR]
Time-like shower : m2=E2-p2>0
MSTP(71) = 0(off)/1(on,default)
PARP(71) = 4.(default); Qps2=Q2*PARP(71)

[Multiple interaction]
MSTP(81) = 0(off)/1(on,default)