Dear bednobs, thanks for your reply.
To be honest, I was still emotional when I was in the police station.
When I was interviewed by a police, I was a bit alike taking him a friend and venting out my emotion. I was puzzled why my wife called the police, and tried figuring out the reason. After coming back home and talking to my wife, I realized that it must be the helpline people who called the police.
I deeply believe that my arrest and caution result from a series of emotional actions and mistakes. I deeply regret that.
As you may or may not know that, there is provision for exceptional case to be removed: appendix 2 of retention guidelines for nominal records on the police national computer. I am wondering whether what kinds of cases are considered as exceptional cases.
When you say "It's like going to court and pleading guilty - you are accepting all the consequences that brings". Does it mean if I want my caution to be removed, I have to go to court?
Regarding the immigration rules, it is immigration rule --paragraph 322(1C,iv).
you can find it from the link
http://www.ukba.homeoffice.gov.uk/policyandlaw/immigrationlaw/immigrationrules/part9/
There are the immigration rules, not law. UK immigration rules always apply retrospectively.
I applied for a position of mentor. I have to get CRB check. Because the caution, I need to get references from others. Later on I found that my two apprentices are taller than me.