A WebCite®-enhanced reference is a reference which contains - in addition to the original live URL (which can and probably will disappear in the future, or its content may change) - a link to an archived copy of the material, exactly as the citing author saw it when he accessed the cited material.
This is a reference card for zsh. It was created based on version 3.1.9 so is a little out-of-date. It is seven pages long, even with three columns per page, so you will need a very big piece of card to stick it to.