Thanks for your reply, Stevo5.
For BettyNoir:
A standard level CRB check will only show convictions, cautions and reprimands.
An enhanced check will also show relevant information from specific bodies (such as the General Teaching Council, or the Nursing and Midwifery Council, as appropriate), together with any information deemed relevant by a senior police officer.
Following the Soham murders, there was much concern that Ian Huntley had previously been questioned about alleged sexual offences but that information was not included on his enhanced CRB check. Police forces now tend to err on the side of caution and include just about everything that they know about someone. For example, I know of a teacher who found that her former partner's sexual offences appeared on her own enhanced CRB check. There has also been a post, here on AB, from a teacher who found that an allegation of 'sexual grooming' appeared on his CRB check, even though he'd never been questioned about it (or even made aware of it).