OptionalcategoryOptional category (e.g. Math & Trig), shown dimmed at the row's trailing edge.
OptionaldetailOptional text shown right after the name, unemphasized — an 'enum' label's value (AVERAGE 1).
OptionaliconOptional icon-pack key for the leading glyph; overrides the NamedItemKind default.
OptionalinsertWhat choosing the row inserts, when that is not name — an 'enum' label inserts its value.
OptionalkindWhat the row is. Defaults to 'function', which is what an omitted kind meant before names joined the list.
The item's canonical name — inserted (with an opening paren, for a function) when the row is chosen.
One row in the formula autocomplete list. Deliberately minimal — the presentational panel needs a display
name, its NamedItemKind, and optionally acategory/ aniconKeyoverride. The row layout is identical for every kind; only the leading glyph distinguishes them.