[mkgmap-dev] postcodes

Hi all, I currently have a list of postcodes added to my map, and can see them in the Postal Code field of the Find Addresses option in basecamp, but they are not linked to any roads/houses, so any address searches with postcodes do not find anything. Can anyone please explain what I need to do to get postcodes working properly? There is a brief mention of mkgmap:postcode in the help, but it doesn't explain how to use it, and anyway, I only have the centre points of the postcodes rather than their enclosing areas. Thanks, Mike