arc42 and ArchiMate layouts in the folder guide; arc42 examples cover all sections; 1.3

references/folders.md gains arc42 (sections as numbered folders and cards,
black boxes, quality tree) and ArchiMate (layers, type in tag and
sublabel, element mapping). Gotchas: ref in every kind needs extension
0.11.0; tags are not drawn on the box.

references/folders.md

@@ -77,6 +77,65 @@ The numbered folders are only for sorting; nothing depends on the names. A team
 
 Component types that fit C4: people are `external`; the system itself and other systems are `cloud` (own) or `external` (others); containers are `frontend`, `backend`, `database`, `messagebus`, `security`; components inside a container use the same set, wrapped in a `region` boundary named after the container.
 
+## arc42
+
+[arc42](https://arc42.org) is a documentation template with twelve sections; four of them are views (diagrams), the rest are text. In a model, the views are folders numbered like their section, the decisions are section 9, and the text sections are `cards` (title plus short items) on the diagram they belong to. Card titles carry the section number so a reader finds each section.
+
+```
+cinema-tickets/
+  main.archify                     section 3 business context (the system and its neighbours);
+                                   cards 1.1 Requirements, 1.2 Quality goals, 1.3 Stakeholders,
+                                   2 Constraints, 4 Solution strategy, 11 Risks and technical debt,
+                                   12 Glossary
+  registry/
+    people.archify-registry          users and operators
+    systems.archify-registry         neighbouring systems
+    building-blocks.archify-registry each block's description in black-box form:
+                                     "Responsibility: ... Interfaces: ..." (section 5)
+  0300-context/
+    technical-context.archify        channels and protocols; card 3 Domain interfaces
+  0500-building-blocks/
+    level-1.archify                  the system's white box; card 8 Crosscutting concepts
+    booking.archify                  level 2 of one block, linked from its registry entry
+  0600-runtime/
+    book-seats.archify               key scenarios as sequence diagrams
+  0700-deployment/
+    production.archify               building blocks inside boundaries for nodes and zones;
+                                     card 7 Mapping (block -> node)
+  1000-quality/
+    quality-tree.archify             Quality -> characteristics -> scenarios;
+                                     card 10 Quality scenarios (stimulus and response)
+  decisions/                         section 9, one *.archify-decision per decision
+```
+
+Say where each section lives in `model.description`. Cards hold short lines, not prose: an arc42 document with long text belongs next to the model, not in it. `examples/arc42-cinema-tickets/`, `arc42-iot-telemetry/` and `arc42-team-wiki/` (the smallest) are complete.
+
+## ArchiMate
+
+[ArchiMate](https://www.opengroup.org/archimate-forum) models an enterprise in layers. Archify has no ArchiMate notation, so each element is an Archify component type with its ArchiMate type written out: in `tag` (searchable, shown in the focus panel) and in `sublabel` (shown on the box; Archify draws tags only in the focus panel).
+
+```
+insurance-claims/
+  main.archify                     layered view: Business, Application, Technology as three
+                                   region boundaries, top to bottom, three elements each in the
+                                   same columns, serves/realizes arrows between layers
+  registry/
+    business.archify-registry        actors, roles, processes, services, events
+    application.archify-registry     components, services, interfaces, data objects
+    technology.archify-registry      nodes, system software, technology services, networks
+  0100-business/
+    business-layer.archify           actors, roles and services
+    handle-claim.archify             the business process as a workflow (lanes per role)
+  0200-application/
+    application-structure.archify    components, services, interfaces, data objects
+    application-cooperation.archify  how the components talk
+  0300-technology/
+    infrastructure.archify           nodes and networks inside boundaries
+  decisions/
+```
+
+A mapping that reads well: actors and roles `external`; processes `backend`; business and application services `cloud` or `frontend`; application components `backend` or `frontend`; data objects `database`; nodes `backend`, `cloud` or `database`; networks `messagebus` or `security`. Name relationships in connection labels: serves, realizes, uses, accesses, assigned to, triggers. Keep type names short enough for the box (`App Component`, `Tech Service`). `examples/archimate-insurance-claims/`, `archimate-hr-onboarding/` and `archimate-logistics-tracking/` are complete.
+
 ## How the extension knows it is in a model
 
 The nearest folder above a file that contains `main.archify` is the root. Under that root, at any depth: `*.archify` are member diagrams, `*.archify-registry` make up the registry, subfolders are groups. `node_modules` and `.git` are skipped.