Research / Constructs
What happens to each Markdown construct
Markdown Preflight indexes its evidence three ways. The rule set is one claim at a time, the research matrix is one destination at a time, and this page is the one you usually want: you have a table, or a footnote, or a diagram, and you need to know which of the five editors will survive it.
Every verdict below is the worst observed outcome for that construct across the destinations named, from one fixture pasted into five real editors on 2026-08-24.
| Construct | What happens across the five | Rules |
|---|---|---|
| Tables | a manual step in Substack, X, and LinkedIn; kept in WordPress and Beehiiv | 10 |
| Footnotes | a manual step in WordPress, Substack, Beehiiv, X, and LinkedIn | 5 |
| Math | untested in LinkedIn; a manual step in WordPress, Substack, Beehiiv, and X | 5 |
| Images | a manual step in WordPress, Substack, Beehiiv, X, and LinkedIn | 8 |
| Links | untested in LinkedIn; a manual step in WordPress, Substack, Beehiiv, and X | 23 |
| Obsidian syntax | untested in LinkedIn; a manual step in WordPress, Substack, Beehiiv, and X | 5 |
| Code | degraded in X and LinkedIn; kept in WordPress, Substack, and Beehiiv | 8 |
| Headings | a manual step in WordPress; changed in X and LinkedIn; kept in Substack and Beehiiv | 6 |
| Lists | degraded in Beehiiv; changed in WordPress, Substack, X, and LinkedIn | 8 |
| Inline formatting | degraded in X and LinkedIn; kept in WordPress, Substack, and Beehiiv | 5 |
| Front matter | a manual step in WordPress, Substack, Beehiiv, X, and LinkedIn | 5 |
| Raw HTML | untested in LinkedIn; a manual step in X; degraded in WordPress, Substack, and Beehiiv | 5 |
| Mermaid diagrams | untested in LinkedIn; a manual step in X; degraded in WordPress, Substack, and Beehiiv | 5 |
| Quotes, dividers, and line breaks | changed in X and LinkedIn; kept in WordPress, Substack, and Beehiiv | 9 |
How to read this
A construct with a manual step in every destination is not a broken construct, it is one no editor accepts from the clipboard: footnotes and math both have working native controls in several of these editors, and the step is using them. A construct marked untested has no dated test behind it on that destination, which is reported rather than guessed.