• [url=URL]text[/url] to write a link
• [img]URL[/img] to put in an image
• [details=summary]hidden[/details] (or [spoiler]) to hide something
• [b]bold[/b] and [i]italic[/i] for text formatting
• [sup] and [sub] to ^superscript or _subscript
• paragraphs are separated by two blank lines
• [pre][code]some_thing()[/code][/pre] to write computer code
• [s]deleted[/s] to cross something out
• [quote]text[/quote] for text that someone else wrote
• [quote=URL]text[/quote] for text that you want to link from somewhere else