{
  "port": 541,
  "protocol": "both",
  "service": "uucp-rlogin",
  "oneLiner": "Registered as uucp-rlogin; essentially never seen in the wild.",
  "whatItIs": "IANA registers TCP and UDP 541 as \"uucp-rlogin\", with no description beyond the name — an rlogin-style entry point associated with UUCP, the store-and-forward system that moved mail and files between Unix hosts over dial-up before the internet was ubiquitous. Regular UUCP over TCP lives on port 540. There is no widely deployed software listening on 541 today, so an open port here is almost certainly something unrelated that picked the number, not UUCP.",
  "exposure": {
    "verdict": "never",
    "note": "If something really is answering here, identify it before anything else — an unexplained listener on an abandoned legacy port deserves investigation, not internet exposure."
  },
  "checkCommand": "nc -vz -w 3 TARGET 541",
  "links": [
    {
      "title": "IANA Service Name and Transport Protocol Port Number Registry — 541",
      "url": "https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=541",
      "kind": "iana"
    }
  ]
}