The current content model of <teiCorpus> is: teiHeader, ( ( model.resourceLike+, ( TEI | teiCorpus )* ) | ( TEI | teiCorpus )+ ) ) That is, you may *either* have a series of 1 or more <TEI> and <teiCorpus> elements, intermingled; OR you can have one or more of <facsimile>, <fsdDecl>, <sourceDoc>, and <text> elements intermingled followed by zero or more <TEI> and <teiCorpus> elements intermingled. This is exactly the same as saying teiHeader, model.resourceLike*, ( TEI | teiCorpus )* except that it requires at least one child <TEI>, <teiCorpus>, <facsimile>, <fsdDecl>, <sourceDoc>, or <text>. In the new <standOff> world, we have voted to make <TEI> a member of model.resourceLike. Thus we have to alter the content model of <teiCorpus> because as written it would be ambiguous (if a <TEI> is your first child after <teiHeader>, you don't know which branch of the content model you are in). It is not too difficult to solve the ambiguity problem: teiHeader, ( ( model.resourceLike+, ( teiCorpus, ( TEI | teiCorpus )* )? ) | ( teiCorpus, ( TEI | teiCorpus )* ) ) ) I am pretty confident this content model validates the same set of documents (and, perhaps as importantly, rejects the same set of documents) as the original content model (with <TEI> in model.resourceLike). I am not against using this content model. But it occurs to me that a) it is a bit cumbersome b) the set of documents permitted is already screwy c) it looks very different from the content model of <TEI>, which (in the new world order) <teiCorpus> is very similar to. One possible solution is to 1) add <teiCorpus> to model.resourceLike, too; and then 2) change content model of <teiCorpus> to match that of <TEI> (in the new standOff world): teiHeader, model.resourceLike+ This has the advantage of having a very clean, understandable content model for <teiCorpus> (and no ambiguity). It has the disadvantage that it allows for even more screwy things. E.g. <teiCorpus> <teiHeader> <standOff> <TEI> <facsimile> <TEI> <teiCorpus> <TEI> <facsimile> <TEI> <teiCorpus> <facsimile> </teiCorpus> It has the feature (which some will consider an advantage, others a disadvantage, I'm sure) that <TEI> and <teiCorpus> become the same thing. Just as an XSLT stylesheet can have an outermost element of xsl:stylesheet or xsl:transform, no difference, a TEI document will be able to have <TEI> or <teiCorpus> as an outermost element, no difference. Same goes at every level of nesting where one is allowed: so is the other, and it can have the same content. Personally, I still think putting <TEI> into model.resourceLike was probably a mistake, but once we've done that, I'm inclined to say throw <teiCorpus> in there, too.