Proposed text change to core spec, associated w Errata issue #4

The issue is about Sec 5.42 of the core spec:

     
http://docs.oasis-open.org/xacml/3.0/xacml-3.0-core-spec-os-en.html#_Toc325047147

    

    The issue was raised on the email list entitled:

      Subject: Re: [xacml] Issue: Ambiguity in defn of
      Request wrt Attributes Category,

     and Erik suggested, and I agreed that it should be handled in the
    Errata:

      https://lists.oasis-open.org/archives/xacml/201303/msg00004.html

    

    Sometime after the issue was posted on the wiki for Errata (issue
    #4):

        4 Multiple Category Elements

      https://wiki.oasis-open.org/xacml/XacmlErrata

    

    Erik added the following comment:

    'Note from Erik: The core spec is intended to operate
      only on single instances of a given attribute category.

        Anything else is specified in the multiple decision profile.

        This is stated in section 5.42 

      

            "There may be multiple <Attributes> elements with the
      same Category attribute

               if the PDP implements the multiple decision profile, see
      [Multi].

              Under other conditions, it is a syntax error

                if there are multiple <Attributes> elements with
      the same Category (see Section 7.19.2 for error codes)." '

    
    I agree that the above text addresses the issue, but I believe there
    is still a problem

    that the text is located in the wrong place.

    

    The problem is that I raised this issue when I was actually
    implementing this use case

    as part of the OpenAz project upgrade to XACML 3.0, and I was using
    the core spec

    for guidance, but did not see the text that Erik quoted above.

    

    In retrospect, after reading Erik's note to errata,

     the reason that I didn't notice the text was that

      I was looking for the rules governing use of the
    <Attributes> element

       in the part of sec 5.42 that describes the <Attributes>
    element that says the following:

    "<Attributes>   [One
      to Many]

               Specifies information about attributes
      of the request context by
      listing a sequence of <Attribute>
      elements

                  associated with an attribute
      category.

               One or more <Attributes>
      elements are allowed.

               Different <Attributes>
      elements with different categories are used to represent
      information

                 about the subject, resource, action, environment
      or other categories of the access
      request."

    
    Unfortunately, this text does not say anything about the syntax
    error condition, that is described

    in the header part of Sec 5.42.

    

    By comparison, the next child element of the Request element, is
    described as follows:

    "<MultiRequests>  
      [Optional]

                     Lists multiple request
        contexts by references to the <Attributes>
      elements.

                     Implementation of this element is optional.

                     The semantics of this element is defined in [Multi].

                     If the implementation does not implement this
      element,

                        it MUST return an Indeterminate result if it
      encounters this element. See section 5.50."

    
    i.e. in this case the description of the child element contains the
    complete description,

    including what constitutes an error and how it should be handled,
    and where to

    find more info.

    

    Therefore, my recommendation is to move the text quoted by Erik
    above, from the

    header section of 5.42, and append it starting on a new line
    immediately following the

    current text that describes the <Attributes> element. This
    will make the <Attributes> element

    description consistent in scope w other elements, such as the
    <MultiRequests> described

    above i.e. put the whole description of the child element in one
    place,

     not divided between the header and the element descriptions.

    

      Thanks,

      Rich