SF Symbols

Over 7,000 system symbols with free platform consistency, Dynamic Type alignment, and accessibility — the default answer to "we need an icon." This skill covers using them well, authoring custom ones that behave like system ones, and the animation vocabulary. (Animation implementation patterns live in design/animation-patterns → symbol-effects.md; this skill owns selection, authoring, and rendering.)

When This Skill Activates

• Choosing icons for tabs, toolbars, buttons, widgets ("should this be an SF Symbol?" — usually yes)
• A needed glyph doesn't exist → authoring a custom symbol
• Rendering a changing value (signal, progress, volume) as a symbol
• Symbol state changes that should animate (mute/unmute, play/pause)

Using system symbols