InfoPreserver is organized by operating capability, not by subject popularity or modern technical sophistication. The same broad subject can appear at several A-levels because a hand method, a workshop method, and a regional infrastructure method have different dependencies. A hand pump, powered pump manufacture, and a municipal pumping station are related, but they do not belong in the same recovery stage.
Start with the real situation. Ask what resources, tools, trained people, energy, materials, safety controls, and institutions are actually available. Then choose the lowest folder where the method is genuinely usable. Lower placement is not inferior; it is usually more resilient.
| Stage | Operating Context | Placement Test |
|---|---|---|
| A0 | Day one and immediate survival | Useful now with carried, found, or improvised resources. |
| A1 | Stabilized community | Useful with hand tools, local materials, salvage, skilled labor, and simple power. |
| A2 | Industrial seed | Reliable powered workshops, standardized parts, controlled processes, or sustained electrification are mandatory. |
| A3 | Infrastructure recovery | Regional networks, public works, grids, institutions, or coordinated specialist systems are mandatory. |
| A4 | Advanced industry and science | Precision facilities, high-purity supply chains, advanced computing, or specialty science are mandatory. |
| A5 | Frontier systems | Research capability exceeds ordinary advanced-industry practice. |
Each PDF receives one primary leaf folder. Cross-domain usefulness should be preserved through tags, related links, and editorial notes, not uncontrolled duplicate copies.
An unqualified capability name belongs to the earliest useful form. Higher-level folders must state the dependency that raises the level: industrial, electric, precision, municipal, high-purity, networked, frontier, or another real requirement.
If a useful form was routinely practiced before grid electricity or modern machine tools, an A0 or A1 form should usually exist. This is why blacksmithing, casting, passive solar, water power, soapmaking, latrines, manual printing, hand copying, and electrical salvage appear below A2.
| Need | Start Here | Then Inspect |
|---|---|---|
| Immediate survival | A0 Core Survival | A0 Salvage and Repair; Navigation and Signaling |
| Community sanitation | A1 Hygiene and Sanitation | A1 Water Systems; A2 process-control forms |
| Power recovery | A1 Energy Basics | A1 Electrical Salvage; Workshop Transition; A2 electrification |
| Making and repair | A1 Workshop and Repair | A1 Salvage; A2 Manufacturing and Metalworking |
| Long-term rebuilding | A1-to-A2 transition folders | A2 industrial seed; A3 regional infrastructure |