The modules.taxonomy block — the running config, or a profile's own.
The layer judged.
The category field and, when declared, the sub-category field — each keyed by where it is declared (the layer's override, or the taxonomy) —; none when the layer is not bound or the taxonomy is disabled.
The taxonomy's declared fields for one layer, under its reader's rule.
The rule is applied to the shape the symbol injector hands the resolver at load time —
{ layerId, properties }—, so a name that only a nestedproperties.attributesholds is not called carried: no reader of the icon would see it there.