i went to my local nick and they told me what was on the pnc about me anyway! so i asked them if they could print it off and sign it which she almost did until someone else told her she was't allowed ..........anyway, they gave me all the info about what to do, i have had to apply for a "subject access" report at the cost of £10, just thought i would let people know for future refrance.

No, the whole record gets weeded - the fiche is destroyed and the PNC record is deleted so there is "no trace" of the person in Crimnal Record Office files. The idea of weeding the records is that if the person has not been convicted/cautioned for a certain length of time, and their original offence was not considered that serious, then the record should not kept any longer.
To retain just the CRO number on PNC would cause complications because no-one would know what the original offence was, and as we see with threads on here, all the details of the conviction are needed at times. Better to have absolutely no trace, rather than a partial trace with no details.

Hope that explains it a bit

I would keep quiet about having been told that info as the officer who revealed the information risks the sack for doing it.
They shouldn't even tell you, never mind printing it off - breach of all the Data Protection rules. One of those real no-nos that causes a sharp intake of breath!

But yes, the way to get a copy of what the police in the UK have on file about you is to get in touch with your local police HQ and ask for a Subject Access check - usually done through the Data Protection Office. Or look on your local Force website as most of them have Subject Access forms online now.