So I was having a think s'morning, this is a universal able to read format, whatever your PC is, eg Apple or Mac etc. So I explored and found immediately a PDF reader on my PC but not a PDF writer. Explored some more and eg Word, can save in .doc format but also can save in .pdf format. So if I am ever sending a document to loads of recipients (as likely as that sounds) I now know how to format it for everybody