Re: [dita] DITA XML Schema backwards compatibility and conformance

[Eliot Kimber <ekimber@reallysi.com>]

Eric Sirois wrote:

> Does it make sense to have a conformance statement for ISO 8601?  Should 
> XSDs help enforce the conformance statement in  this case, knowing that 
> once DTDs validated documents would possibly be invalidated once the are 
> validated against XDSs?  

I think that it would be inappropriate for the normative schemas to be 
more restrictive than the DTDs since that could indeed break documents. 
Unless the current Toolkit is already validating those values (I'm 
pretty sure it's not) it would definitely come as a surprise to many 
users to have documents fail that did not fail before.

One thing I will point out is that in some scenarios documents may go 
from being DTD-validated to being schema validated with no direct user 
involvement (for example, a CMS might export originally-DTD-based docs 
as schema-based docs or use schemas for internal validation). That means 
that a user who authored a DTD-validated document could have that same 
document fail somewhere else simply because it was rebound to a schema.

I think it would be appropriate to highlight the issue in the 1.2 spec 
and provide both an option in the Toolkit to validate the values and 
provide a variant version of the schemas (or some sort of switch) to 
turn on the validation, for the benefit of those users who do want to 
prepare for a time when these data types in particular will be validated.

I think that for interoperability it is appropriate to define a specific 
data type for dates, in particular, but I think we've already lost the 
opportunity to be as strict as we might like.

Cheers,

Eliot

-- 
Eliot Kimber
Senior Solutions Architect
"Bringing Strategy, Content, and Technology Together"
Main: 610.631.6770
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