This page sets and reads cookies for testing cross-subdomain fireproofing (eTLD+1). Two cookie types are available: parent-domain scoped (shared across subdomains) and host-only (scoped to the exact hostname).
Scoped to the eTLD+1 (e.g., domain=first-party.site). Visible from all subdomains.
Scoped to this exact hostname (e.g., www.first-party.site). Not visible from other subdomains.