If you've selected a site on the map and encountered the message "No title found," it indicates that the land is not registered in The Land Registry system.
Not all land is registered. This could be for a number of reasons. For example, the land may have been in the same ownership for many years and the event triggering its first registration, such as a sale or mortgage, has not occurred. However, The Land Registry do have details of more than 20 million registered properties in England and Wales, a number that increases every day. But there are still millions of properties that have not yet been registered and The Land Registry do not hold information on them.