- From: Jeni Tennison <jeni@jenitennison.com>
- Date: Sat, 27 Apr 2002 10:36:01 +0100
- To: "Don Smith" <donalds@isogen.com>
- CC: "Schema" <xmlschema-dev@w3.org>
Hi Don, > What is the purpose of the "final" attribute on an element > declaration? > > I understand its use on a type definition, but can't figure out what > it means to prohibit a derivation from a declaration. An element declaration is "derived" from another when its part of the *substitution group* of that element declaration. Controls like final, abstract and (partially) block determine whether an element can or can't be (or has to be) the head of a substitution group. Setting final to true means that it can't be cited as the head element of a substitution group; setting abstract to true means that the element itself can't be used in the instance, but has to be substituted by some other element. Cheers, Jeni --- Jeni Tennison http://www.jenitennison.com/
Received on Saturday, 27 April 2002 05:36:03 UTC