Radar
Web: /search (Radar). Public discovery like Instagram Explore — posts from public accounts worldwide, not only people you follow. Posts and Flights tabs, plus people and hashtag search.
Private accounts never appear on Radar or hashtag discovery (even if you follow them). Blocked users stay hidden. Private logbook entries never appear.
Mobile does not have a full Radar/Explore screen yet — use Feed, profiles, and search entry points that exist on mobile.
Mentions & hashtags
Use @username in captions, bios, notes, status captions, and comments.
Use #hashtags in captions; they become discoverable on web Radar.