Briefings and Reviews are separate public collections. Their source folders mirror their canonical routes, and every folder has a reader-facing index.md.
Briefings
site/content/briefings/index.md→/briefingssite/content/briefings/{slug}.md→/briefings/{slug}
A Briefing declares collection: briefings and format: Briefing. Multi-item editions use the editorial date as the canonical filename and title.
Reviews
site/content/reviews/index.md→/reviewssite/content/reviews/paper/index.mdand{slug}.md→/reviews/paperand/reviews/paper/{slug}site/content/reviews/topic/index.mdand{slug}.md→/reviews/topicand/reviews/topic/{slug}
A Review declares collection: reviews and either format: Paper Review or format: Topic Review. Paper Reviews provide substantially deeper source-centered analysis of one paper, preprint, or tightly bounded research contribution than a Briefing introduction. Topic Reviews center a research topic, theory, or research program across multiple contributions.
The current corpus does not justify subject subfolders within Briefings or either Review subtype — field states subject coverage without duplicating that taxonomy in the URL, and adding a subject folder still requires a meaningful reader-facing index and real content. This is a different question from the per-topic subfolder below, which decomposes one Topic Review’s own content rather than splitting the reviews/topic/ index itself.
A Topic Review may graduate from a single file to its own subfolder. A Topic Review starts at site/content/reviews/topic/{slug}.md. Once its reconstruction needs standalone pages for formal apparatus specific to that research program (not reusable enough across contexts to become a general Concept — see Information architecture in DESIGN.md), it moves to site/content/reviews/topic/{slug}/index.md → still /reviews/topic/{slug}, the same route and the only entry the /reviews/topic hub lists. Each apparatus page sits alongside it as site/content/reviews/topic/{slug}/{apparatus-slug}.md → /reviews/topic/{slug}/{apparatus-slug}, reachable only by link from the reconstruction page. A satellite page carries no collection, format, date, or field — it is not independently listed anywhere — but keeps unlisted: true until it has passed the same human review every other page requires, since that flag also governs exclusion from the generated content index, sitemap, and RSS regardless of collection membership. entanglement-bootstrap/ is the first Topic Review using this pattern.
Compatibility routes
Pages moved from /investigations/** retain those locations as aliases. The former /investigations and /research hubs redirect to /briefings; former Review and source-companion paths redirect to the matching Review page. Internal links use only the new canonical routes.