I find it incredible that the outside machine requires users to have an intimate knowledge of how to text on a mobile phone in order to enter a registration number in full - with no instructions provided. I'm not sure if I prefer the version I used today (in Bicester) which has a button for every number and letter - but not arranged in any sort of conventional keyboard style (it has 3 or 4 vertical columns!). I'm not sure that was much better. It all seems to be rather a lot of overkill just to avoid a few people passing on their tickets.