{
  "about": "Where every figure on a Painted Court print and page comes from. Retrieved dates are when this build read each source.",
  "sources": [
    {
      "id": "osm",
      "what": "Every court outline, and the paths, trees, fences and buildings round it",
      "name": "OpenStreetMap",
      "by": "OpenStreetMap contributors",
      "url": "https://www.openstreetmap.org/copyright",
      "licence": "Open Database License (ODbL) 1.0",
      "credit": "© OpenStreetMap contributors, ODbL",
      "retrieved": "2026-10-11"
    },
    {
      "id": "nominatim",
      "what": "Club search, on submit only, one request a second, no autocomplete",
      "name": "Nominatim usage policy",
      "by": "OpenStreetMap Foundation",
      "url": "https://operations.osmfoundation.org/policies/nominatim/",
      "retrieved": "2026-10-11"
    },
    {
      "id": "overpass",
      "what": "The survey of one club: the FOSSGIS main instance, and VK Maps' public instance when the main one is busy",
      "name": "Overpass API instances",
      "by": "FOSSGIS e.V.; VK",
      "url": "https://wiki.openstreetmap.org/wiki/Overpass_API",
      "endpoints": [
        "https://overpass-api.de/api/interpreter",
        "https://maps.mail.ru/osm/tools/overpass/api/interpreter"
      ],
      "policy": "Main instance: under 10,000 queries and under 1 GB a day, with a 30 second pause after a 429. VK Maps: \"Feel free to use our services in any project. There are currently no requests limitations.\"",
      "retrieved": "2026-10-11"
    },
    {
      "id": "tennis-tagging",
      "what": "How a court is tagged (leisure=pitch, sport=tennis, ref, surface), and the guide the refusal links to",
      "name": "Tag:sport=tennis",
      "by": "OpenStreetMap Wiki contributors",
      "url": "https://wiki.openstreetmap.org/wiki/Tag:sport%3Dtennis",
      "licence": "CC BY-SA 2.0",
      "retrieved": "2026-10-11"
    },
    {
      "id": "itf-rules",
      "what": "The court's lines (Rule 1: 23.77 x 10.97 m doubles, 8.23 m singles, service lines 6.40 m from the net) and the scores the studio accepts (Rules 5 to 7, Appendix VI)",
      "name": "ITF Rules of Tennis 2026",
      "by": "International Tennis Federation",
      "url": "https://www.itftennis.com/en/about-us/governance/rules-and-regulations/",
      "retrieved": "2026-10-11"
    },
    {
      "id": "vincenty",
      "what": "Every length: the inverse geodesic on the WGS84 ellipsoid",
      "name": "Direct and inverse solutions of geodesics on the ellipsoid with application of nested equations",
      "by": "T. Vincenty",
      "published": "Survey Review XXIII (176), 88-93, April 1975",
      "url": "https://doi.org/10.1179/sre.1975.23.176.88",
      "retrieved": "2026-10-11"
    },
    {
      "id": "geodtest",
      "what": "The receipt for every length: 300 geodesics the engine is tested against to 1 mm (src/engine/geodtest.dat)",
      "name": "Test set for geodesics",
      "by": "Charles F. F. Karney",
      "published": "2010",
      "url": "https://doi.org/10.5281/zenodo.32156",
      "file": "https://sourceforge.net/projects/geographiclib/files/testdata/GeodTest-short.dat.gz",
      "sha256": "31d376e8158f7af26277d887d7a1e7726e14d172db5a848a1730dd4886ab6121",
      "licence": "CC0 1.0",
      "taken": "200 short lines (3001-3200) and the first 100 random lines under 15,000 km",
      "tolerance": "1 mm",
      "retrieved": "2026-10-11"
    },
    {
      "id": "fonts",
      "what": "The type: Big Shoulders Display for numbers, scores and headings; Public Sans for text; Gloock for titles on Gilt and Watercolour",
      "name": "Big Shoulders Display, Public Sans, Gloock",
      "by": "The Big Shoulders Project Authors; The Public Sans Project Authors (USWDS); The Gloock Project Authors (Duarte Pinto)",
      "url": "https://fontsource.org/",
      "licence": "SIL Open Font License 1.1",
      "retrieved": "2026-10-11"
    }
  ]
}