The Markdown syntax documentation for Jira Cloud does not cover table markup yet.
If you add or edit an issue description or comment through REST API or Automation, starting a line with a pipe character `|` and putting another one between cells and one at the end, Jira will recognise this as a table row. This does not work in the frontend editor (anymore), there you could type `/tab` or hit Shift+Alt+T. That‘s probably why it’s not documented.
However, Jira does support a header row (and column) in tables in the frontend editor. It is sometimes suggested that all you would need to get this from Markdown, is a second row whose cells only contain a run of hyphens `-` (as in many other Markdown syntax extensions) – this is wrong!
| Column Header | Column Header |
| ------------- | ------------- |
| Cell Content | Cell Content |
Through guesswork, trial and error, I found that you need to use double pipes instead:
|| Column Header || Column Header ||
| Cell Content | Cell Content |
Actually, every cell that is preceded by a double pipe will be treated as a header cell (i.e. `th` in HTML), so one can also get row headers:
| || Column Header |
|| Row Header | Cell Content |
Has this been documented by Atlassian anywhere?
Is there any other undocumented Markdown syntax, e.g. for setting column widths or their horizontal alignment, or for adding colored status codes?
