Thanks for the info (& apologies for not conducting a 'simple search' of the forum!)
I actually wanted to ask a support team the question and went through the over complicated 'support' ask a question route, only to be led to post in a forum.
Would have been useful if whilst requesting a certain blog name which appears as simply 'reserved', if there was actually some explanation of what that means! If it would have said as you suggest, that the name was an old blog and therefore cannot be used, job done, no need to bother anyone with a question.
By the way, how do you know that the name I wanted was once a blog anyway, or are you just making the assumption?
Also, is there no way to actually email a question to WordPress support directly? :s