Is there some definition around the attributes that are returned from the Lists.GetListItems? I am able to view the attributes retuned just fine but I am wondering if they would ever change?
Here are some examples of what I am seeing... @ows_Author, @ows_FileDirRef, @ows_PermMask
I would like to build some classes around these values and my concern is that if they are not published somewhere Microsoft may up and change them or some setting in Sharepoint may.
It is possible that they change as sharepoint (major) version changes. Every change is possible then.
Don't think it would happen in minor version.
However they may also change depending on what list you query. But fields your mentioned and many other fields are basic fields that every list will contain.
If you want to view field data yourself (for example, what Type they are), download Sharepoint Manager - it's invaluable tool for a developer.
These are internal field names for default SharePoint fields. Unless you explicitly change them, they will remain the same.
Micheal Yeager's blog has a table which describes these fields and their data types: http://blogs.msdn.com/michael_yeager/archive/2008/11/03/reference-list-for-internal-field-names.aspx