Research / Rules / SUB-MERMAID-01
SUB-MERMAID-01
Mermaid stays as source code; no diagram renders. This applies to Substack, where the result is degraded.
Affects Substack. Matches mermaid. Fixture markdown-portability-test-v1.
What happens, per destination
| Destination | Tested surface | Result | Severity | Confidence | Last tested |
|---|---|---|---|---|---|
| Substack | Substack web post editor | Degraded | Review | Verified | Tested 2026-08-24. |
Why, and what to do
The source survived as a code block but did not render as a diagram.
Do this: Export the diagram as an image and keep a text summary.
Limits of this rule
- It describes the surface and date in the table above, not every version, theme, or plugin.
- Reading it in isolation hides the other rules that touch the same draft.
- A rule is only as current as the test date beside it.
Related
- All Substack rules, and the Substack test record.
- The full rule set, also available as rules.json.
- Check your own draft against all five