Well there's properly and properly...
Think I saw that one of the recommended books was Helen Osborn's. She gives examples of 3 levels of recommended standard citations. If there was a law enacted that the most rigorous had to be used, then I think this would soon be a less popular hobby!
The lesser levels don't require too much extra work, though, and, as has been said earlier, would be useful if you ever needed to explain where you got a piece of information when posting on here