Dear TEI-List,

I have a question about Module 12 (Critical Apparatus) and would be  
grateful if any of you were so kind as to clarify it.

I am trying to complement the witnesses identification in the  
<listWit> element (within the <front> matter) with a full structured  
description, supplied in <msDesc> and <biblStruct> (within the  
<sourceDesc> element of the <teiHeader>).
The Guidelines suggest using a <ptr> with a @target.

My doubt is: where exactly should I place the @xml:id that will  
identify each @wit in the various <rdg> elements of <app>?
Do I have to put the @xml:id in <witness> (within <listWit>) or may I  
put it in each <msDesc> and <biblStruct> (within the <sourceDesc>) and  
then use a <ptr> in <witness>, pointing to the <sourceDesc>?

Will the apparatus work perfectly well, if I do this?

    <msDesc xml:id="B">
         <!-- full description of manuscript one -->
    <biblStruct xml:id="A">
         <!-- full description of printed document one -->
    <biblStruct xml:id="C">
         <!-- full description of printed document two -->

<!-- bellow in the front matter-->
           <witness>Printed document one <ptr target="#A"/></witness>
           <witness>Manuscript one <ptr target="#B"/></witness>
           <witness>Printed document two <ptr target="#C"/></witness>

<!-- bellow in the text body -->
          <rdg wit="#A #B">some text</rdg>
          <rdg wit="#C">text here</rdg>

I am sorry if this obvious, but I would like to have your validation.

Thank you very much for all the help,
Elsa Pereira