In SharePoint 2010 (as well as other versions) with Publishing enabled, you have an SPWeb.Navigation.TopNavigationBar object. This represents the links you see in the Top Link Bar, and is a collection of SPNavigationNode objects. One of the properties of SPNavigationNode is "Properties", a Hashtable. An example Property is "NodeType". Since it's a Hashtable, there can be one, zero, or many Properties for each Node. My question is, where do I find a list of the common Properties used?
I don't think there is any official documentation about that. After decompiling DLLs, this is what I found :
Microsoft.SharePoint.Navigation.SPNavigationNode.Properties are coming from
The latter gets those properties from an internal class, which seems to point to
OWSSRV.dll that I cannot decompile.
Your best bet would be to get the properties from different objects and check for yourself what is returned. Or try searching the Internet for that subject and gather what you can from different sources.