Document formatting and comments

Formatting

Code blocks

• Colours are only how the editor shows the text. They are never saved, never sent to collaborators and never appear in exports; the stored code, its revision and comments on it stay exactly what was typed.
• Code is never run. Markup such as <script> in a block stays text.
• Blocks longer than 20 000 characters are shown without colours so typing stays responsive.

Math

• Math is block math: one display formula per code block. Inline math inside a paragraph is not available yet; it needs a new kind of content and will come with a later document schema.
• The formula is drawn by KaTeX, bundled with the app at a fixed version with its fonts, so showing it loads nothing from other sites. Commands that could link, load or style (\href, \url, \includegraphics, \htmlClass, \htmlStyle and similar) are refused and shown as plain text.
• A formula KaTeX cannot read shows Cannot show this formula with the reason, above its source, in that block only; the rest of the page is unaffected and nothing is changed. Sources longer than 10 000 characters are shown as source only.
• The stored content stays the LaTeX source, so history, comments, Copy and agents see exactly what was typed.

CSV and Markdown previews

• CSV is read strictly (RFC 4180): commas separate cells, a cell containing a comma, quote or line break is wrapped in double quotes, and "" is a quote inside it. A stray quote, an unclosed quote or a row with a different number of cells than the header is reported with its line, and the source stays shown. At most 500 rows, 50 columns, 2 000 characters per cell and 100 000 characters in all.
• Markdown shows headings, emphasis, strikethrough, inline and fenced code, lists and checklists, quotes, rules, tables and links. Raw HTML is shown as the characters that were typed, never as HTML. Images are shown as [Image: description] and are never loaded. Only http, https and mailto links become links; they open in a new tab. At most 20 000 characters, 12 levels of nesting and 5 000 elements.
• Cells and text are only ever text in the page: nothing in a CSV cell or a Markdown source can add markup, run script or fetch anything.

Diagram and chart previews

```mermaid
flowchart LR
  Draft --> Review --> Published
```

{
  "type": "bar",
  "title": "Runs per week",
  "x": ["W1", "W2", "W3"],
  "series": [
    { "name": "Research", "values": [12, 18, 9] },
    { "name": "Support", "values": [7, 4, 11] }
  ]
}

• Mermaid is bundled with the app at a fixed version and loads only when the first diagram is shown. It never draws in the page itself: it draws in a hidden frame whose security policy allows no requests at all, so whatever a diagram’s styles or shapes name (images, icons, masks, fonts), the browser does not fetch it, from other sites or from the app. Text labels only: click callbacks and links do nothing, HTML in labels stays text, and a diagram’s own %%{init}%% directive or front matter cannot change these settings or restyle the page. The drawn SVG is cleaned again before it is shown (no scripts, links, embedded HTML, images, use references, overlays or styles that load a URL) and is kept in its own isolated subtree, so its styles only affect the diagram.
• As a second layer, a diagram that names something to load is refused with Cannot show this diagram: it refers to an image, icon, URL or escaped text: image and icon shapes (A@{ img: … }, A@{ icon: … }, quoted keys too), sequence diagram properties, url(…), image-set(…), cross-fade(…) and image(…) in styles and class definitions, and any backslash.
• Diagrams are drawn one at a time. At most 5 000 characters, 150 connections (arrows and links, in every diagram type), 300 statements, 50 subgraphs and nesting 6 deep (subgraphs or composite states). When a diagram takes longer than half a second to draw (or to fail), edits by others no longer redraw it automatically: the block says The source changed and redraws when you choose Preview. Once previews on one page have taken a second in all, further blocks show their source and say Previews on this page took long to draw; choose Preview to draw one.
• A chart is read strictly: type is bar or line, x lists the category labels, and every series has a name and one finite number per label. Unknown keys, wrong types and specs over the limits are refused with the reason. At most 8 series, 200 points per series, 200 characters per label or name, values up to ±1e300 and 50 000 characters in all. Labels are only ever text.
• Series use the product’s chart colours, in order. The chart is announced to screen readers with a summary (type, title, series, categories and value range); Show data table under it lists every value, and hovering a bar or point shows its value.
• A diagram or chart that cannot be drawn shows Cannot show this diagram or Cannot show this chart with the reason, above its source, in that block only. Switching between Source and Preview never changes the document.
• Comments on a diagram or chart anchor to text in its source, as in any code block. Commenting on a single diagram node or chart bar is not available: it needs a new kind of content and will come with a later document schema.

Canvas

Editing together

Export

Comments

• Anyone who can read the document can read its comments.
• Commenting, replying and resolving need Comment or Edit access. On private output only its owner comments; a workspace owner’s audited read never includes commenting.
• Restricted members can read comments on output in their custody but cannot comment, reply or resolve, the same as editing.
• A document holds at most 1000 comments (threads and replies, 10 000 characters each); each thread can be resolved or reopened 100 times. A commenter does not share the editors’ save rate limit. Comments count toward the workspace’s artifact storage budget.
• Comments never change the document’s content or revision. When the quoted text is edited the thread follows it; when it is deleted the thread shows as text removed.