watermark with css?

[sienteasturias]

First forgiveness by English, hope that understand me!
Os wonder if somehow power make watermark in imagenes which post forum through URLs with <img> laden server image host or Instead enable something andalusia save departing blank ie bearing Clearcoat!

Hope that this a good asking thanks!

[Dismounted]

Marking images using CSS would be ineffective, as anyone would be able to get the image without the watermark anyway.