Page cache compatibility
Default: off.
Turn this on if you use a full-page cache (WP Rocket, LiteSpeed Cache, Cloudflare APO, a host-level cache) and visitors report seeing the password screen after unlocking.
It appends a single-use query argument after a successful unlock so the cache serves a fresh page rather than its stored copy of the password screen. The password screen itself always sends no-cache headers.
Admin bar indicator
Default: on.
Shows “Site protected” or “Site public” in the WordPress admin bar while you browse, with a padlock icon, linking to the settings screen. Only administrators see it.
It is a small thing that prevents a common and expensive mistake: launching a site while it is still locked, or believing it is locked when it is not.