http://dev.w3.org/2006/waf/widgets-digsig/#locating-signatures
4.3 > If the signatures list is not empty, sort the list of signatures by the file > name field in descending order (e.g. signature001.xml followed by > signature9.xml followed by signature.xml). How do you sort signature009.xml and signature9.xml? The proposal is to only allow [1-9][0-9]*, which should solve this. And validators should complain about archives containing files of the form "signature" [0][0-9]* ".xml"
