What about "s" for spoilers?
And how to escape the square brackets?
Does it work if there is no closing tag like here
or does it need a backslash \[b\]like here\[/b\]?

Can we quote?
>With just one right angle bracket/"greater than"?
>>329 should link to OP's post.
>>>/art/29463 would be a cross-link to another board.

How to create a direct image link?
Just plain URL: https://boards.guro.cx/art/src/1649436583494.png
Or with square brackets: [https://boards.guro.cx/art/src/1648701255487.jpg]
May be double square brackets: [[https://boards.guro.cx/art/src/1648088738480.jpg]]
Or with right angle brackets/"greater thans" too: >https://boards.guro.cx/art/src/1646926025469.png
>>https://boards.guro.cx/art/src/1646926025469.png
>>>https://boards.guro.cx/art/src/1646926025469.png

If none or only some of the above lines work, could someone please give the necessary advices?