Where do I fine the namespace definition for storage format?

[iamgoingtosneeze]

I am trying to bulk create pages in confluence as we migrate to using it; however, I cannot build the storage documents properly as storage format contains the ac:  and ri: namespaces. Where can i find definition of these? Or a dtd 

[Nic Brough _Adaptavist_]

There is no context given in your question - for most of us, you need to frame it by explaining what you are trying to do, what you mean by "storage document" and "namespaces", and explain why you're not using the REST API as documented