I can make some improvements to the documentation, so that this is clearer. “state” describes where the AppDomain currently is among the various times in the lifetime of an AppDomain, so thi sis a state descriptor and not an attribute.

I can make the following changes in the topic:

1)
I can update the description of state from "Current state of the AppDomain. See the Remarks section of this topic for more information." to "A descriptor for the current state of the AppDomain. An AppDomain can be in one of several possible states from creation to deletion. See the Remarks section of this topic for more information."

2)
I can change the description of E_APPDOMAIN_SINGLEUSER from "The AppDomain is ready for use by a single user to perform DDL operations." to "The AppDomain is ready for use in DDL operations. These differ from E_APPDOMAIN_SHARED in that shared AppDomains are used for SQLCLR executions as opposed to DDL operations. Such AppDomains are isolated from other concurrent operations."

Does that help?
David Schwartz
dschwart@microsoft.com