Wordpress API variables sent in post

I did a quick search but couldn't find the solution here, forgive me if this has been asked before.

I remember a way to add vars in a Wordpress post by adding something like [gallery=22] in the wysiwyg editor... anybody know 开发者_运维技巧where I can find the documentation on this?

Thanks.

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That's the Shortcode API - http://codex.wordpress.org/Shortcode_API