Disposition of I18N comments for Structures

1.   Easy addins

Issue

Allow easy retro-fitting of internationalisation markup to schemas defined without them

Resolution

The <redefine> mechanism provides precisely the requested functionality:

• xml:lang can be added to types defined without it;
• Bidi markup can be added to types with mixed content which did not provide for it as defined.

Limitations

Elements defined with simple types cannot be redefined to have mixed content.

Amelioration

The type library will define a text type, and the Primer will recommend its use. This has mixed content and allows any internal markup.

2.   Character Répertoires

Issue

How to constrain the character répertoire of character data in (regions of) XML documents.

Resolution

No targetted provision for character répertoire support will be provided in XML Schema v1.0.

Rational

There is not consensus in the WG about supporting Character Répertoires in principle -- those not in favour express some surprise the I18N should encourage such a non-i18n-friendly feature. In any case there is no architectural locus for pervasive scoped specification of répertoires. In other words, this would not be a simple add-on, but would require non-trivial innovation in our architecture.

Workarounds

It is possible to restrict the character répertoire of strings in a simple type using a regular expression. There are at least two weaknesses with this solution:

• It's not scoped, and so may require repeating large regular expressions many times.
• It doesn't cover the character content of mixed content types.

Many people in the WG feel that the problem of typing the character content of mixed content needs to be addressed, but we have agreed to postpone this until v1.1 because:

• Substantial work would be involved.
• Worries about return to CR.
• Not consensus that we should do this at all.