When true (and the group is a package) the package's member listings are hidden from buyers, tickets, and confirmation emails — only admins see the breakdown.

When true the group is a bookable "package": its member listings can carry per-listing price overrides (the group dimension of listing_prices) and fixed per-package quantities (group_listings.quantity).

When true one group scan checks in every member listing the ticket holds.

When true the group's public booking page also offers member listings marked Hidden (the long-standing behaviour). When false a hidden member stays off that page — internal to admin and capacity, bookable only through its direct link. Ignored for packages: a bundle is one product built from its members, so they always stay.