What does Epic's public documentation say about how the Derived Data Cache decides an entry is invalid or must be regenerated?

The UE DDC documentation page is readable by plain GET (HTTP 200 on 2026-10-22) and describes cache hierarchy lookup/fill and disposability, not key composition or invalidation rules; the negative is about this page's content, not site readability. Curator qualifications: Record Epic readability per URL and date; do not generalise 'Epic docs unreadable' (AUDIT2/AUDIT4 hints); other Epic pages (F-08 Unreal pages 403, K6-05) not re-tested here. Absence of invalidation rules in public docs is a bounded negative for pages read. Limitations: One page. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://dev.epicgames.com/documentation/en-us/unreal-engine/using-derived-data-cache-in-unreal-engine",
      "note": "UE docs: Derived Data Cache page (GET 2026-10-22T00:04Z, HTTP 200)"
    }
  ]
}