Proposal: add character attribute text:display=true|none

Hi all,

I'd like to add a character attribute 'text:display', which would allow 
you to optionally hide text (value 'none', value 'true' otherwise) . We 
already allow text:display attributes on some special elements, but this 
has previously not been a character attribute that would allow this to 
be generally applied to any text. The name and values are derived from 
XSL-FO, which has a similar attribute (but with more values, I believe).

The feature to hide text itself can be used to 'customize' documents, 
where you hide certain text to create different versions of the file. 
Hiding text is supported in other standards (XSL-FO, CSS) as well as in 
other word processors.

Relax-NG:
<define name="style-text-properties-attlist" combine="interleave">
<optional>
<attribute name="text:display">
<choice>
<value>true</value>
<value>none</value>
</choice>
</attribute>
</optional>
</define>


Sincerely,
Daniel