diff --git a/docs/file-format-parity.md b/docs/file-format-parity.md
index ce464cc58..915ebc126 100644
--- a/docs/file-format-parity.md
+++ b/docs/file-format-parity.md
@@ -18,7 +18,7 @@ from the public specifications, and users' own `.ai` files are used locally only
 | | Illustrator | VectorCraft | Notes |
 |---|---:|---:|---|
 | Formats opened or placed | ~30 | 26 | missing: FreeHand, CorelDRAW, DWG, HEIC/HEIF, JPEG 2000, PICT, Pixar, Word `.doc`, PS |
-| Formats saved (Save As) | 6 (AI, AIT, PDF, EPS, SVG, SVGZ) | 6 + native | `.ai` written PDF-compatible (no Illustrator editing data) or as legacy version 7 (layers and groups, one artboard per file) |
+| Formats saved (Save As) | 6 (AI, AIT, PDF, EPS, SVG, SVGZ) | 6 + native | `.ai` written PDF-compatible (with an editing copy of the art: layers, groups, paths, colors, artboards) or as legacy version 7 (layers and groups, one artboard per file) |
 | Formats exported | ~16 | 17 | missing: DWG, 3D (OBJ/USDA/glTF); extra: GIF/PNG-8 palette export, DXF up to 2018, layered PSD |
 | **Overall (weighted by use)** | | **~75%** | `.ai` and PDF dominate the weighting |
 
@@ -49,8 +49,13 @@ private editing data. VectorCraft:
   A PDF-compatible `.ai` opens on its PDF part's trim boxes (its artboards), the bleed boxes round them
   becoming the document's bleed, so art in the bleed shows outside the artboard, within the bleed guide (#1266).
   A PDF saved with its editing data (`AIPDFPrivateData`) opens the same way.
-- **Writes** a PDF-compatible `.ai` (Save As › `ai`): Illustrator opens it as plain art. It never writes
-  Illustrator's private editing data, which is undocumented.
+- **Writes** a PDF-compatible `.ai` (Save As › `ai`). With the option `editingData` (on by default, Include
+  Editing Data for Other Apps) every page's `PieceInfo` also carries an editing copy of the art in
+  `AIPrivateData` streams, in the form VectorCraft's `.ai` reader reads: layers and sublayers, groups, paths with
+  their fills and strokes (a compound path as one path of all its subpaths), process, spot and global colors, swatches and color groups, guides,
+  hidden and locked objects, object names and every artboard with its name. Type, gradients, patterns, images,
+  symbols, clipping groups and live objects are written as plain filled and stroked paths, each with a warning;
+  transparency and effects other than geometry effects are left out.
 - **Writes** a legacy `.ai` of version 7 (Save As › `ai` › Version: Legacy (version 7), `aiVersion: "7"`): the
   PostScript form, from the published *Adobe Illustrator File Format Specification* version 7.0
   ([PRONOM fmt/423](https://www.nationalarchives.gov.uk/PRONOM/fmt/423)), which apps reading `.ai` open with its