on Wikipedia

• "indoor positioning system"
• "Bluetooth LE beacon"
  • "Bluetooth LE §Proximity sensing"
• "Ultra-wideband §Real-time location"
  • "List of UWB-enabled mobile devices"
• "Nearables"
• "Local positioning system"
• vendor-specific versions
  • Apple iBeacon — Bluetooth LE beacon + UWB
  • Google's Eddystone-UID and -TLM — Bluetooth LE beacon
• Bluetooth beacons with embedded URLs ended up being a failed experiment that was discontinued in 2018

elsewhere

• "Bluetooth LE 5.1 and Direction Finding" on Albata Technologies, a "digital cockpit and connected mobility" company
• "Bluetooth beacon" on Amazon
• "What is a beacon" on kontakt.io, an indoor location services company
• "Bluetooth location tracking and positioning" on Inpixon, an indoor data company