CAP Normative Schema is improperly defined

Title: Message

The normative XML 
Schema in the CAP specification is improperly defined and will either generate 
validation errors or be rewritten to a form which conforms to XML Schema 
when input to common XML Schema processing tools. A major 
source of the problems is the fact that what should be anonymous simple types in 
the CAP schema are encoded with "name" attributes and are thus not anonymous. 
For instance, the CAP schema defines the element msgType as:

 

<element name = 
"msgType">

  <simpleType name = "msgType" 
>

    <restriction base = 
"string">

    ...

    
</restriction>

  </simpleType>

</element>

 

A proper definition 
of the msgType element would *not* include the "name" attribute in the 
"simpleType" element. Thus, the proper definition would be:

 

<element name = 
"msgType">

    
<simpleType>

      <restriction 
base = "string">

      ...

      
</restriction>

    
</simpleType>

</element>

 

   This improper use of XML Schema occurs at least 10 
times in the CAP schema (I may have missed a 
couple...)

    Given that most well written XML Schema processors will 
rewrite or reject the normative CAP schema, it is hard to understand the 
justification for proposing a standard that contains a flawed normative 
definition. In this case, for interoperability to be had, it is necessary to 
assume that all XML Schema processors will either ignore or rewrite the 
offending elements of the schema in a consistent manner. While this appears to 
be the case so far, it introduces a risk of interpretation that is not 
appropriate for a standard such as CAP. For a standard such as CAP, it must be 
recognized that misinterpretations of CAP messages can lead to life-or-death 
consequences. Such a standard should only be accepted if it has achieved 
the highest possible levels of clarity and 
quality.

 

        bob wyman