Updated the access level conformance units and write mask conformance units. Write mask deals with other attribute in all node classes. Access level only deals with the variable mask for the variable value field.

I think I would like the text for "WriteMask", "UserWriteMask", "User Access Level Full", and "User Access Level Base" to REALLY emphasize the distinction. For me, it takes a few re-reads to understand the differences between these four. I'm thinking aloud... what do you think about the following descriptions:

Address Space WriteMask: Supports the WriteMask attribute, which describes the write-access availabilities for all attributes on a given node, including unsupported attributes.

Address Space UserWriteMask: Supports the UserWriteMask attribute, which describes the write-access availabilities for all attributes on a given node, for the current user, which may include unsupported attributes. Server must provide at least 2 distinctions of user (e.g. admin and user). The access is the same, or more restrictive than described by the WriteMask attribute.

Address Space UserWriteMask Multilevel: An extension of "Address Space UserWriteMask" where the server provides multiple levels of access per node, i.e. more than 2 users.

Address Space User Access Level Base: Provides user-level security to the Value attribute of Variable nodes. (Question: the current text talks about an indication of Read(), Write(), HistoryRead(), and HistoryUpdate() --- what is an "indication" in this case?)

Address Space User Access Level Full: An extension of "Address Space User Access Level Base" which provides multiple levels of user access per node, i.e. more than 2 users. (Question: same as above)

fixed in doc 1.02.11 ( Text usually is only to provide reference to specification that describeds the functionality in detail)

Reviewed changes in 2012-11-27 telecon.