{
  "schema_version": "1.0",
  "published_at_utc": "2026-10-22",
  "local_test_date": "2026-10-21",
  "product": "DWG Version Switch",
  "methodology": "Anonymized single real engineering DWG opened with licensed AutoCAD 2027 Core Console; native SAVEAS to target DWG versions; independent reopen + header + basic entity/table inventory; no drawings shared.",
  "sample_count": 1,
  "source_format": "DWG 2013 (AC1027)",
  "source_size_bytes": 2318398,
  "source_unchanged_by_sha256": true,
  "converters_executed": 7,
  "conversions_passed": 7,
  "autoCAD_openings_checked": 8,
  "cad_inventories_passed": 8,
  "baseline_entity_count": 3043,
  "real_DWG_browser_tests_passed": 10,
  "outcomes": [
    {
      "transition": "DWG 2013 → DWG 2007",
      "dwg_header_from": "AC1027",
      "dwg_header_to": "AC1021",
      "opened_in_AutoCAD_2027": true,
      "entities_original": 3043,
      "entities_output": 3043,
      "entity_type_counts_unchanged": true,
      "layer_counts_unchanged": true,
      "layout_entity_counts_unchanged": true,
      "units_unchanged": true,
      "drawing_extents_unchanged": true,
      "anonymous_block_identifiers_changed": true
    },
    {
      "transition": "DWG 2013 → DWG 2018",
      "dwg_header_from": "AC1027",
      "dwg_header_to": "AC1032",
      "opened_in_AutoCAD_2027": true,
      "entities_original": 3043,
      "entities_output": 3043,
      "entity_type_counts_unchanged": true,
      "layer_counts_unchanged": true,
      "layout_entity_counts_unchanged": true,
      "units_unchanged": true,
      "drawing_extents_unchanged": true,
      "anonymous_block_identifiers_changed": true
    },
    {
      "transition": "DWG 2013 → DWG 2010",
      "dwg_header_from": "AC1027",
      "dwg_header_to": "AC1024",
      "opened_in_AutoCAD_2027": true,
      "entities_original": 3043,
      "entities_output": 3043,
      "entity_type_counts_unchanged": true,
      "layer_counts_unchanged": true,
      "layout_entity_counts_unchanged": true,
      "units_unchanged": true,
      "drawing_extents_unchanged": true,
      "anonymous_block_identifiers_changed": true
    },
    {
      "transition": "DWG 2013 → DWG 2004",
      "dwg_header_from": "AC1027",
      "dwg_header_to": "AC1018",
      "opened_in_AutoCAD_2027": true,
      "entities_original": 3043,
      "entities_output": 3043,
      "entity_type_counts_unchanged": true,
      "layer_counts_unchanged": true,
      "layout_entity_counts_unchanged": true,
      "units_unchanged": true,
      "drawing_extents_unchanged": true,
      "anonymous_block_identifiers_changed": true
    },
    {
      "transition": "DWG 2013 → DWG 2000",
      "dwg_header_from": "AC1027",
      "dwg_header_to": "AC1015",
      "opened_in_AutoCAD_2027": true,
      "entities_original": 3043,
      "entities_output": 3043,
      "entity_type_counts_unchanged": true,
      "layer_counts_unchanged": true,
      "layout_entity_counts_unchanged": true,
      "units_unchanged": true,
      "drawing_extents_unchanged": true,
      "anonymous_block_identifiers_changed": true
    },
    {
      "transition": "DWG 2013 → DWG R14",
      "dwg_header_from": "AC1027",
      "dwg_header_to": "AC1014",
      "opened_in_AutoCAD_2027": true,
      "entities_original": 3043,
      "entities_output": 3043,
      "entity_type_counts_unchanged": true,
      "layer_counts_unchanged": true,
      "layout_entity_counts_unchanged": true,
      "units_unchanged": true,
      "drawing_extents_unchanged": true,
      "anonymous_block_identifiers_changed": true
    },
    {
      "transition": "DWG 2007 → DWG 2018",
      "dwg_header_from": "AC1021",
      "dwg_header_to": "AC1032",
      "opened_in_AutoCAD_2027": true,
      "entities_original": 3043,
      "entities_output": 3043,
      "entity_type_counts_unchanged": true,
      "layer_counts_unchanged": true,
      "layout_entity_counts_unchanged": true,
      "units_unchanged": true,
      "drawing_extents_unchanged": true,
      "anonymous_block_identifiers_changed": true
    }
  ],
  "known_changes": "4 anonymous block identifiers renamed on SAVEAS in each output; some older outputs added APPID records.",
  "caution": "ONE real drawing tested. Equal counts/limits and successful reopening do not prove preservation of attributes, XREF, Civil 3D/AEC proxy objects, dimensions, layouts' visual fidelity, or 1:1 semantic geometry. Users must audit drawings before professional delivery.",
  "private_data_policy": "Client files, paths, raw hashes, actual entity labels, and detailed CAD inventories are kept private. This report includes only aggregated technical outcomes."
}