OptionalheadOptional header cell class (e.g. ledger__head-num for numeric columns).
Which row field this column renders and how.
Localization key for the column header label.
OptionaltooltipOptional localization key for the header tooltip (spells out an abbreviation).
CSS grid track width — a single token (no internal spaces).
One column in a Mystical Ability sub-type's Being-sheet ledger (#990).