Which of the following connectors should be carefully taped for weather protection when used outdoors?
Why No common coaxial connector used by hams is truly waterproof in field service, so any outdoor connection should be sealed with tape or self-amalgamating tape and weatherproof sealant. Water that wicks into a connector soaks the coax dielectric and braid, raising loss and SWR and eventually ruining the feed line. The UHF (PL-259), BNC and Type N families all need this treatment, so sealing every outdoor connector is the right practice.
Watch out Type N is often called weather resistant because of its gasket, which tempts people to leave it bare, but it is only resistant, not sealed, and still needs taping when exposed.
If it lives outside, wrap it. No ham coax connector is waterproof by itself.