Thanks for a concise and well written document. I have not run tools to validate the XSD and the XML artefacts but the definitions all look reasonable. Comment: - What does the following mean in the definition of e164StringType? It is indeed the intention to use "x"? What is the reason for having e164Type, why not use e164StringType? Nits: - What are "Organization transform commands"? This phrase appears several times in 3.4 an it seems this refers to what section 4.2 describes later on. Well, if you read the document sequentially, things are a bit confusing. Perhaps define upfront what transform commands are? It might also be that EPP people are used to "transform commands" and this just shows my lack of familiarity with EPP. - s/ement/element/ - s/Zero of more element/Zero of more elements/