Three fragments added this session needed a word the author did not write: an
untitled :::warn told the reader nothing about being a warning, an untitled
panel fell back to whatever the browser calls <details>, and the contents list
had no label at all — an accessibility gap as much as an untranslated one. None
of them could be fixed, because `t` needs a language and Fragment had none, so
those words could only ever have been English on a site that serves Bengali.
Fragment gains Lang, captured on each call at parse time — a node renderer never
receives the parse context, the same constraint that put pictures and headings
on the node. Five phrase keys follow, and a Bengali page now reads সূচিপত্র,
সতর্কতা and বিস্তারিত where an English one reads Contents, Warning and Details.
The demo's own list.html was the better example of the problem and now shows the
answer: a site's own sentences are not in the engine's phrase table, so a
template needing its own words branches on the language it was given. That is
what theme-contract.md has always told a theme to do, demonstrated rather than
asserted, and a case proves the Bengali listing carries no English.
Two files crossed the size advisory on the way. render.go shed the contract
types to view.go, where state.md already claimed they lived and where the file's
own header said they belonged; shortcodes_test.go split to mirror its sources,
which the one-file-per-source convention already asked for. Both are pure moves.
The engine's half is one call: parse the name, hand it to a single `icon`
fragment, decide nothing else. No icon table in Go, ever. The surveyed engines
split three ways — Unicode (Hugo, Pandoc), a remote image per icon (Jekyll's
jemoji, which fails the sovereignty test outright), and inlined SVG from a
bundled set (MkDocs Material) — and all three are decisions about markup, which
ADR-0036 puts in the theme. A theme wanting Font Awesome ships a sprite in its
own base.html and redefines one fragment: no webfont, no request, no script.
The boundary rules are the whole difficulty, because the colon is the commonest
punctuation in technical prose. A name must start with a letter, hold only
letters, digits, hyphens and underscores, and neither colon may touch an
alphanumeric. Verified on the real binary that 10:30:15, key:value:pair,
"Note: this", a URL and a code span all come through untouched — each of them
would otherwise be a silent edit to someone's sentence.
The literal fallback closes the same hole from the other side: when the theme
renders nothing, the engine writes the author's `:name:` back, so an
unrecognised icon is never deleted from the middle of a paragraph.
An icon needed its own inline node rather than the block one — goldmark
distinguishes the two by type — which also avoids the type switch CLAUDE.md §6
forbids: two kinds, two renderer functions.
The reference theme maps six names to Unicode and ships no sprite, font or
asset. core 2794/2800, ext 1615/2000, 34 gates green.