We’ve reblogged this illustration from Boyfriend and ExBoyfriend BDSM Gallery. He’s got great taste in NSFW pics too.
This is a regular series of illustrated guides. You can find the others here.
Although the 1996 Peter Greenaway film The Pillow Book was an erotic and poetic look at body writing, in BDSM it is usually a form of degradation, and it is humiliating insults and not poetic prose that get written on the bottom (and usually photographed).