http://www.bbc.co.uk/news/uk-24321716

I always thought it was a legal nicety for when they got back to you with a proper charge or not

A caution isn't to be taken lightly. Perhaps the name needs changing to another term but for someone in my position, it's something I would have to declare. The problem is that younger people might accept a caution believing it to be just a warning and not realise its implications until much later.

Apparently if you refuse the caution they either have to drop charges or charge you. At least you have the opportunity to plead your case rather than admit guilt by accepting a caution.