One block, rendered: its resolved status, its presentation metadata, its slots (recursive), its form, and its own findings.

outcome is the outcome this block produces for the slot it sits in, when the parent's type declared a slot_outcome_key for that slot and this block's config holds a well-formed outcome name there; nil otherwise, which is every block whose parent declared nothing. It is resolved here rather than by a consumer so that the picture-drawing side reads one field instead of a metadata key plus a config lookup, and so it never learns that core.on_event is the type with an outcome.

join_label is what the join marker under a side-by-side arrangement reads: the string this block type's join_label callback returned for this block's config, normalized by StatifierBlocks.BlockType.join_label/2, and nil when the type declared none or the callback answered with something the refusal set rejects (ADR-0002 amendment B). It is resolved here for the same reason outcome is - the rendering side reads a string and never learns that core.parallel is the type with a completion rule.

It is derived for every node, including the ones whose slots stack and never draw a marker: a field that exists only sometimes is a field every consumer has to remember to guard, and entry.layout already says whether the marker is drawn. An unresolvable block reaches nil by the ordinary route rather than by a special case - its entry is the placeholder's, which declares no callback.

title is the author's own name for THIS block - the value of a declared :string field keyed label - and nil when the type declares no such field or the config holds nothing usable there, which is every block in the core.* vocabulary. nil rather than "the entry's label repeated" so that the card can tell the two apart: a block with a name of its own reads as its name over its type, and a block without one reads as its type alone rather than as its type printed twice (ViewModel.title/1 and ViewModel.subtitle/1 are that pair). It is derived here for the same reason outcome is - the rendering side reads a string and never learns which key an author's name lives under.

invoke_type is what this block's config carries under invoke_type, when that is a non-empty string. It is a config key rather than a type name, so a host type that calls out to a handler gets the same third line core.invoke does by carrying the same key, and no component learns that core.invoke exists. Whether the value is WELL FORMED is validate_config/1's question and its answer arrives as a finding on the same card; hiding the string while a finding complains about it would be the card disagreeing with the form.