I began a PhD in 2012 but withdrew from the course last year due to a recurring health problem (from which I'm now recovered). I spent some time considering my options and came to the conclusion that a PhD is still something I very much want to do. I started looking for positions which might be of interest and have recently found one that I'd like to apply for. I'd appreciate any advice on how to explain on a CV / covering letter etc. that I'd already started a PhD but withdrew from the course in such a way that I wouldn't be hindering my chances.

On a separate issue, I don't want to put all my eggs in one basket by applying for just one post, but how many different applications would it be advisable to make?