Sabaki supports a subset of Markdown in the comments. If you're not familiar with Markdown, I suggest you read the original syntax documentation by John Gruber. Markdown is very straight-forward and simple to learn.
To make a simple line break in Markdown, normally you'd have to end the line with two spaces, but this is not required in Sabaki.
Code blocks don't work in Sabaki. Images will be simply converted into links. HTML input is not allowed.
Sabaki will automatically create clickable links for URLs and email addresses.
Board coordinates can also be detected automatically. Hovering over them will show the position on the board.
As of Sabaki v0.12.3 you can link to specific moves in the main variation by
move number. Just write # followed by the move number and Sabaki will
automatically create a link, e.g:
> Soon after Shuusaku released his last move #127, although Gennan seems calm,
> however his ears suddenly got red. This is a natural response from the human
> body when one is in panic, Black must have played an outstanding move.