OK, still can't get a working redaction

[David E Nedrow <nedlist@grandviewtheatre.net>]

I'm still trying to figure out a mechanism for redacting elements in  
DocBook markup.

Basically, I would like to do something to handle redaction via  
attribute manipulation, such that the following sentence ...

Hi, I'm <personname redact="true"><firstname>David</ 
firstname><lastname>Nedrow</lastname></personname>.

... renders as ...

Hi, I'm XXXXXXXXXXXX.

Or the variant ...

Hi, I'm <personname><firstname redact="true">David</firstname><  
lastname redact="true">Nedrow</lastname></personname>.

... which renders as ...

Hi, I'm XXXXX XXXXXX.

... where the Xs would render as a solid black field the size of the  
redacted element. Eg., a redacted image would be rendered as a black  
area equal to the dimensions of the image element that would have been  
rendered.

I think my confusion primarily is caused by not being clear on where  
this would actually happen.

I want to keep the actual markup as simple as possible, and handle all  
the processing in my customization layer. So, should I somehow create  
a new attribute as shown above, or a new inline similar to the  
'cleartext' example in DocBook 5 Guide. An attribute that applies to  
certain (or possibly all?) elements would be better in my mind.

The second part of this is, where do I make the magic happen after an  
element to be redacted has been parsed? Would this actually be handled  
by the XSL stylesheets, or the rendering engine (XEP in my case)? Or a  
combination of both.

Is this actually a question for RenderX (XEP vendor)?

-David Nedrow