I'm writing on behalf of the TEI Technical Council with a question about your practices regarding the @version attribute on <TEI> and <teiCorpus>.
During an evaluation of the datatype of the @version attribute – which is teidata.version – we discovered a number of difficulties regarding the current version numbering practice
in the dev branch, which includes appending the letter “a” (for alpha), for example, “4.1.0a”. This makes it invalid for a document to claim, by way of this attribute, that it is valid against the development version of the TEI Guidelines (as some TEI customizations
wish to do). We also realize that the current definition of teidata.version does not match the syntax of the popular Semantic Versioning system (which, for example, would use “4.1.0-alpha” instead).
We would like to ask
* whether you use the @version attribute on <TEI> and <teiCorpus> at all?
* if you do, how do you use it (e.g. do you point to a specific released version of the Guidelines, e.g. 4.0.0)?
* would your work flow be negatively affected if we removed the @version attribute on <TEI> and <teiCorpus>, or would it be sufficient to indicate a specific version using the
xml-model processing instruction or the <schemaRef> element?
One course of action we are considering on this issue is to deprecate the @version attribute on <TEI> and <teiCorpus>, and to provide guidance on referencing the TEI version
which was used in the creation of a document using <schemaRef>. Another is to require that the @version attribute of a document that conforms, for example, to TEI version 4.4.0 have a value that starts with “4.4” and otherwise matches the Semantic Versioning