I started writing this documentation back in 2011 during my brief tenure at Internet Archive. The project on which I was working was going to need the IAS3 API and, to be frank, I found the existing documentation lacking.
After I left the Archive this documentation collected dust in my Dropbox for a couple of years. Then, when I started to archive San Francisco Perl Mongers videos on Internet Archive I frequently found myself referring to this doc, particularly the discussion on metadata fields.
While I now use Jake Johnson's ia-wrapper Python script for my uploading, this documentation may still be very useful to others who'd like to programmatically maintain items on Internet Archive. Therefore I've given this doc a quick clean-up and have released it on Github for ease of reference and collaboration.
I will do my best to keep this documentation up of date, but I fear it may already be incorrect in many places. Most of this documentation was created by me sifting through the IAS3 code to find methods, fields, values, error messages, etc. Since I left the Archive I no longer have access to that code (it's not yet available on their Github), making it difficult to keep this document in sync. Hopefully, after I finally have v1.0 of the doc out the door, I'll be able to coordinate with IA to keep the doc updated.