Struct Fragment 

pub struct Fragment {
    pub concept: Concept,
    pub key: &'static str,
    pub variant: Variant,
    pub depth: Depth,
    pub locale: &'static str,
    pub audience: Option<Audience>,
    pub title: Option<&'static str>,
    pub body: &'static str,
}

A unit of content, addressed by (concept, key, variant, locale).

Fields

concept: Concept

Concept this fragment belongs to.

key: &'static str

Sub-topic within the concept, e.g. "no-word-splitting".

variant: Variant

How this fragment renders its idea.

depth: Depth

Summary fragments always show; Reference only at reference depth.

locale: &'static str

BCP-47 locale tag. English ("en") is the canonical-complete base.

audience: Option<Audience>

None = shared (default); Some(_) = audience-specific divergence.

title: Option<&'static str>

Optional section heading for reference rendering (e.g. "Quoting"). None for inline fragments (the Foundations spine renders under its concept header instead). Used by render_syntax_reference.

body: &'static str

Markdown body.