Also as someone else pointed out the same complaints that JSON Schema "isn't in the standard, it's a separate standard" apply to XSD. It is still a different st

Also as someone else pointed out the same complaints that JSON Schema "isn't in the standard, it's a separate standard" apply to XSD. It is still a different standard even though during the height of XML mania it sometimes seemed like XSD was inseperable. XML did have DTD baked in, and maybe the author meant DTD in that section, but that was even worse than XSD (and again both were why RELAX NG happened).