Try a google search on Cautions, Just found this on one site
Some coppers I have been told say things like 'its only a caution, its only recorded locally, it won't affect your later life, its nothing'
Just to get you to sign the form causing as little paperwork as possible.
A caution is actually a conviction and you are on the systems for life with at least 3 reference numbers including a national and international ( schengen when it goes live for the UK and for the commonwealth) CRO number (criminal records office).
People should be aware that a caution isn't a let off or a chance it can stain your character forever.
Sorry to sound doom and gloom but people should think carefully before accepting a caution to get out of custody quickly.
Good luck whatever happens.