referrerpolicy=no-referrer-when-downgrade

BRIDGE_HUB_POLKADOT

polkadot_parachain::chain_spec::bridge_hubs::polkadot

Constant BRIDGE_HUB_POLKADOT 

Source 
pub(crate) const BRIDGE_HUB_POLKADOT: &str = "bridge-hub-polkadot";