Here are additional settings for the particle system.
To bring up options, click "Options":
License
Read more here.
Emission Extras
Pre-run is used to pre-run the system so that particles can be visible at the first frame. Periodicity Rnd is used to emit particles at random intervals. It is only useful when using a directional emitter with Direction Spread at zero.
Random Seed
The random seed controls all random parameters in the effect. It is useful when duplicating the effect and a slight variation of particle positions (etc) is needed. Or when the animation just doesn't look good, this value can be changed for a variated look.
Glow
Only active when particle type is Glow Sphere or Star. Glow Size is the relative size for the glow compared to the particle. Opacity, Feather and Transfer Mode controls the look of the glow.
Grid Emitter
Only active when the Grid or Layer Grid emitters are used. Controls how many particles are in each direction of the grid. The emission style can be set to Periodic Burst, meaning that an entire grid of particles is emitted at once, or Traverse, meaning that one particle at a time is emitted while the grid is traversed in order.
Light Emitters
When emitter type is set to Light, these controls are active. Only lights that start with a certain name are used as emitters, that name can be selected here. Here can also be chosen how particles/sec is modified by the properties of the individual light.
Smokelet Shadow
Only active when particle type is Smokelet. RGB controls the color of the shadow. Color Strength is how this RGB is blended with the original color of the particle. Opacity is the opacity of the shadow. When a light with the same name as "Light name" is in the composition, that light will be used to control the location of the shadow. The "Shadow-light" can be a point or parallell light.
Aux System
When the Aux System is in use, these settings are active. Emit Probability is how many of the main particles actually produce Aux particles. Inherit velocity means how much the Aux particle should inherit velocity from tha main particle that creates it. Start and Stop Emit is used to limit the creating of Aux particles over the lifetime of the main particle.