I'm exploring samples from the OpenEHR CKM app (http://openehr.org/ckm/) and see that XML schema namespace for the OET templates is "openEHR/v1/Template". Where that XML Schema is hosted?
As far as I understood, the "openEHR/v1/Template" namespace points to an XML template schema definition for version 1.0.1 which is not available for download (http://www.openehr.org/releases/1.0.1/its/XML-schema/)
Tried to use OET XML Schema taken from 1.0.2 distr (http://www.openehr.org/releases/1.0.2/its/XML-schema/) but sample template OET files taken from CKM do not pass v1.0.2 XML schema validation.
Which OpenEHR template XML schema is actual and up-to-date?
Check the Ocean Template Designer, under Template Designer\Schemas. I think what you are looking for is CompositionTemplate.xsd
Also check the Java libs, oet-parser component: https://github.com/openEHR/java-libs/tree/master/oet-parser/src/main/xsd
Take into account that OET is an internal format of the Ocean Template Designer, in software you should be using Operational Templates (OPTs) that can be generated from OET templates.
You might find other usefull XSDs on my knowledge repo. I took some of the openEHR XSDs and flattened them to make automatic XML validation development easier: https://github.com/ppazos/knowledge