Presentation

[b]…[/b] — bold type
[i]…[/i] — italic
[u]…[/u] — underlined
[s]…[/s] — strikethrough

[code]…[/code] — code block
[spoiler]…[/spoiler] — spoiler block
[spoiler=…]…[/spoiler]
[source]…[/source] — colorcoded block, assuming C#
[source=…]…[/source] — colorcoded block, specific language^[which?]

Links

[img]http://…[/img] — insert image
[url]http://…[/url]
[url=http://…]…[/url]
>>… — link to post by ID
[user=##] — link to user's profile by ID

Quotations

[quote]…[/quote] — untitled quote
[quote=…]…[/quote] — "Posted by …"
[quote="…" id="…"]…[/quote] — ""Post by …" with link by post ID

Embeds