SOAP Version 1.2 Part 2: Adjuncts: what is the "simple authentication feature"?

Hi.
In section 7.5.1.2 of part 2[1], table 17 states for using 401:
| If the simple authentication feature is unavailable or the operation
| of simple authentication ultimately fails, then the message exchange
| is regarded as having completed unsuccessfully.
The document does not define nor reference a simple authentication
feature.
Doing a search for this "simple authentication feature", I found an
old draft of the HTTP binding[2], with an editor note saying:
| At present this is more of a hook, we have not (yet) described a
| simple authentication feature or an HTTP specific expression of that
| feature.
Regards,
Hugo
 1. http://www.w3.org/TR/2003/REC-soap12-part2-20030624/#http-reqbindwaitstate
 2. http://lists.w3.org/Archives/Public/xml-dist-app/2002Jan/att-0089/2001-10-09_TraceFW_HTTP_Binding.html
-- 
Hugo Haas - W3C
mailto:hugo@w3.org - http://www.w3.org/People/Hugo/