Proposal 13011: Add line-through and overline to highlight domain

[Eliot Kimber <ekimber@rsicms.com>]

I have posted this proposal, along with a working version of the hi-d DTD
declarations.

I have implemented the minimum expression of the proposal. However,
reviewing the email discussion, there are two possible enhancements:

1. Add <blink>, so that DITA is complete with respect to CSS/XSL-FO
text-decoration values (other than "none", but see (2)). I know there is
serious distaste for blink as an effect and I have no love for it myself.
But there is a completeness argument to be made.

2. Provide some form of "format none" element, which would correspond to the
text-decoration value "none". Nancy Harrison suggested this addition.

My main concern with "none" is be the potential utility and implementation
complexity. You can always get the same effect by breaking a string into
multiple sets of nested formatting elements, so at best it would count as a
convenience. 

I do have a requirement for a "turn formatting off" element in my Publishing
work, and I have accommodated it through the <roman> element in the D4P
formatting domain. The name "roman" makes sense to publishers but it's not
really a good general name. The primary use case for Publishing is to get
roman text in a context that is otherwise italic. It's a pretty weak
solution to the general problem and I included it primarily as an expedient
for going from Word and to InDesign.

In a more general context, there can be quite a bit of potential complexity
in mapping a nested "no formatting" element into the correct rendition
stuff, as not all output formatters have a direct way to represent it. That
could lead to complex logic to convert a single set of nested formatting
requests into sequences of formatting requests.

My instinct is to leave the "none" value of text-decoration unprovided for
in the absence of a stronger argument for it.

On the other hand, there is also a completeness argument to be made for
including the "none" text-decoration value as well.

Cheers,

Eliot

-- 
Eliot Kimber
Senior Solutions Architect, RSI Content Solutions
"Bringing Strategy, Content, and Technology Together"
Main: 512.554.9368
www.rsicms.com
www.rsuitecms.com
Book: DITA For Practitioners, from XML Press,
http://xmlpress.net/publications/dita/practitioners-1/