Currently, the markup is as follows:
¥yenposting
>>1 Reply Arrows

Inline images:

 [images{https://files.catbox.moe/ncj9ui.gif,(https://files.catbox.moe/rfcuib.gif),https://files.catbox.moe/ffd7m5.gif}] 

Up to 3 images can be put into in an image block, comma separated. Images with their URLs in parentheses will be spoilered.

Text spoilers work as you'd expect
Text spoilers

 **Text spoilers** 

Post quoting, do note that quotes can't be nested:

Block Quotes

 [quot] Block Quotes [/quot] 

Code blocks:

 [code] code blocks [//code] *Without the extra /