COMREF says
hereParticle array format:
[ShapeName,AnimationName,Type,TimerPeriod,LifeTime,Position,
MoveVelocity,RotationVelocity,Weight,Volume,Rubbing,Size,Color,
AnimationPhase,RandomDirectionPeriod,RandomDirectionIntensity,
OnTimer,BeforeDestroy, Object]
so
drop ["\Ca\Data\ParticleEffects\Blood\Blood.p3d", "Billboard", 1, _timetolive,[_pos select 0,_pos select 1,0.75], [_xvel,_yvel,_zvel], 1, 0.05, 0.0045, 0, [_size], [blood_particle_color,blood_particle_color,blood_particle_color,blood_particle_color], [0,1,0], 0.5, 0.05, "", _text, ""]
is missing the animation name, so it should be:
drop ["\Ca\Data\ParticleEffects\Blood\Blood.p3d", "", "Billboard", 1, _timetolive,[_pos select 0,_pos select 1,0.75], [_xvel,_yvel,_zvel], 1, 0.05, 0.0045, 0, [_size], [blood_particle_color,blood_particle_color,blood_particle_color,blood_particle_color], [0,1,0], 0.5, 0.05, "", _text, ""]
(At least, I think!!
)
Hope that helps!!
Luke