# Bone Flow #123 Particle Specification v1.0

- Component: #123 Particle
- Package Version: 1.0.12
- Runtime: BoneParticle 1.0.8
- HTML Functional Class: `bf-particle`
- Status: Development / Candidate

## Formal Expressions

- Snow
- Rain
- Sakura
- Leaves — falling autumn leaves.
- Smoke
- Spark — a thunder/lightning strike. The main strike must stay thin and continuous, with short zigzag segments near the top and progressively longer zigzag segments toward the bottom, and branch like roots. It must not look like a single straight line or scattered tiny sparks.
- Fire — a persistent campfire flame. Use a large outer teardrop flame and a smaller inner teardrop flame animated at a different speed, surrounded by small glowing dot sparks. It must not look like a flying fireball.
- Bubble

## Public Expression

`type` must be one of the eight formal values above. Unknown values, lower-case aliases, arrays, null, and accessor-backed untrusted objects are rejected.

## Responsibility Boundary

#123 owns only particle expression. It does not own:

- #117 Animation
- #120 Trigger
- #121 Timeline
- #124 Filter
- #125 Blend

## HTML Functional Class

The supported `data-particle-type` values are the same eight formal values. No second normal-use class is defined.