The taxonomy is a locked two-level hierarchy comprising seven core classes of causal mechanisms and 33 seeded sub-level rank factors that categorize how content features influence LLM ranking preferences, expandable via an evidence-driven custodian flow.

flowchart TD
    Taxonomy["Rank Factor Taxonomy"] --> C1["Parametric Recall"]
    Taxonomy --> C2["Grounding & Citations"]
    Taxonomy --> C3["Relevance & Semantics"]
    Taxonomy --> C4["Authority & Trust"]
    Taxonomy --> C5["Structure & Layout"]
    Taxonomy --> C6["Temporal Freshness"]
    Taxonomy --> C7["Intent Alignment"]

    C1 --> F1["Entity Association"]
    C2 --> F2["Source Verifiability"]
    C3 --> F3["Latent Topic Overlap"]
    C4 --> F4["Domain Prominence"]
    C5 --> F5["Snippet Extractability"]
    C6 --> F6["Fact Recency"]
    C7 --> F7["Query Task Fit"]