For websites af.co.uk ag.co.uk ai.co.uk az.co.uk As redirectors to longer/different URLs aa.co.uk ae.co.uk am.co.uk ao.co.uk aw.co.uk All other aSOMELETTER.co.uk domains either don't resolve or are for sale. That's the "A"s taken care of. If 25 more people do one letter each, we can map out all the 2-letter usage in no time!