This is my favourite article on AutoNumbering. It’s a really good step by step guide on how to create numbering schemes with really great explanations why things have to be done in a certain order. If you follow this article you will create very solid numbering schemes that will work in your organisation and more importantly will port to other firms.
Why not try and incorporate the schemes with the UKDEG Standard Style names.
http://shaunakelly.com/word/numbering/numbering20072010.html