Pre-Noms (Pre Nominet)
Pre Nom means a domain that was registered before Nominet became in existence as the single origin for all UK Domains. (ie August 2006)
A pre-Nom UK domain name (.co.uk or .org.uk) is any UK domain name that was registered before the 1st August 1996, the date when Nominet (nominet.org.uk) took over sole management of the UK registry.
When a pre nominet domain expires, Nominet will endeavour to contact the registrant. The domain will remain suspended while they do so. If Nominet are unsuccessful in contacting the registrant, they will delete or drop the domain at there discretion. This is a casing point as business.co.uk was in this suspended state for years and was never dropped. Instead it was suddenly registered by Nominet themselves and points to www.on4.com?
Only a single senior member of Nominet decides on which day to drop a batch of pre-noms and the system then randomises those over that day.
For further details about pre-nom domain names on Nominet (nominet.org.uk) website.