Adding attachment to CouchDB's document

CouchDB can be attached some file toward document from 0.9.0.The previous version could make inline attachment,and last version could make some attachment standalone.

So I tested like this:
$curl -X PUT http://hostname/database/document/test.txt?rev=nnn -H "Content-Type: text/plain" -d @test.txt

And this,too:
$curl -X PUT http://hostname/database/document/test.jpg?rev=nnn -H "Content-Type: image/jpeg" --data-binary @test.jpg

That's useful function.I'd like to image&create some cool service using CouchDB.Actually,I had mistake that I couldn't update jpeg file cause of my wrong settings.So I emailed my trouble to offcial mailing list,and I got correct settings.I didn't know "--data-binary" description.The man who answered my question was so kind !!