The reader took only <x:Visible/> from a note's VML shape and vml_xml
wrote every note with a fixed anchor (two columns right of the cell,
four rows tall) and a 108 x 59.25 pt style, so a plain open and save
moved and resized every note box Excel had stored.
Comment gets an optional NoteBox: the <x:Anchor> corners relative to the
note's cell (so the box follows the note when rows or columns move) and
the shape's width and height. The writer puts it back, clamped to the
sheet; notes made here, and boxes equal to the default, keep the
default box.
- Writer: one xl/threadedComments/threadedCommentN.xml per sheet with
comments (thread, replies via parentId, done for resolved, dT when known)
and xl/persons/person.xml (one person per author), with the [MS-XLSX]
relationship and content types. Each thread keeps its legacy note, linked
by the tc={id} author and xr:uid; its body is the text plus replies.
Ids are GUID-shaped and deterministic.
- Reader: keeps dT timestamps (Comment.dates, JSON-compatible), drops
replies whose thread is missing, and reads note visibility from the VML
<x:Visible/> (best effort, broken VML skipped silently).
- Invalid dates are never written. Round-trip and hostile-input tests.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>