FPF Reference

    A.19.SOURCE-SET-SPACE-SUBSTRATE:4.9 - Descriptor maps and distance definitions dock here, but do not replace the space refs

    Preface node heading:a-19-source-set-space-substrate-4-9-descriptor-maps-and-distance-definitions-dock-here-but-do-not-replace-the-space-refs:24577

    What this page is

    This is generated FPF reference text from the specification preface or supporting sections. It helps interpret FPF; it is not FPF Reference product documentation.

    Methodology

    Use it to understand how the specification wants to be read, then return to a route, pattern, or work packet for active work. Cite generated IDs only when the wording changes the task decision.

    Content

    When a neighboring line already uses DescriptorMapRef or DistanceDefRef, dock it explicitly:

    • DescriptorMapRef may realize or qualify the search-side or outcome-side representation requirement, as the current line requires;
    • DistanceDefRef may realize or qualify the metric requirement over that representation on either side, as the current line requires;
    • but neither one replaces SearchSpaceRef or OutcomeSpaceRef;
    • and CharacteristicSpace remains a different kind from DescriptorMap.

    Use this docking rule whenever a reader could otherwise mistake one local representation layer for the whole search-side or outcome-side space reference.

    Last Updated: 2026-06-17 — upstream FPF commit 646b0b9b (github.com/ailev/FPF)