Subitems: records inside records — Who can do what
• Only workspace Admins can make a table subitems or undo it — it's a schema change, checked again on the server.
• The grid follows the child table's own permissions: no create permission means no Add button, no delete permission means no row delete, and fields you can't write render read-only.
• A child table you can't view is left out of the parent record entirely.
• Deleting a parent removes its subitems regardless of your permissions on the child table — ownership wins, because leaving orphans hidden under a deleted parent would be worse.