A declared "what belongs together" tag: the workflow root, a stage, or an
activity declares named groups, and field entries, activities, and actions
opt in via group. Purely advisory — the engine stores and validates names
(unique per level, every reference resolves) and never acts on them; a
consumer decides what a group means for its medium. The same name declared
at several levels is intentional nesting, addressed per level; the engine
never merges them.
A declared "what belongs together" tag: the workflow root, a stage, or an activity declares named groups, and field entries, activities, and actions opt in via
group. Purely advisory — the engine stores and validates names (unique per level, every reference resolves) and never acts on them; a consumer decides what a group means for its medium. The same name declared at several levels is intentional nesting, addressed per level; the engine never merges them.