When a police caution shows up on a CRB check, does it show what it was for,and if not can employers find out?

I got a police caution for possession of cannabis 4 months ago. I have worked for my current employer for 3 years, and now my CRB check needs to be renewed. I know the caution will show but I would like to know if it will show the specific details of my arrest and the offense, and if it does not show, can my employer find out independently via any other means? I am scared I will lose my job because of the nature of the offense, but I truly don't deserve to, being a generally sensible and hard working person. I don't usually tell lies, but I will to save my job. I want to say my offense was drunk and disorderly as drinking is at least legal, please help????