sparqdown namespace
The sd: namespace is the Sparqdown document language's own vocabulary. It covers the document and version classes (sd:Document, sd:Version), the body node classes the parser emits (sd:Section, sd:Paragraph, sd:Link, sd:Image, sd:CodeBlock, sd:UnorderedList, sd:OrderedList, sd:Strong, sd:Emphasis, …), and the document-structure predicates that connect them (sd:title, sd:body, sd:children, sd:text, sd:linkTarget, plus the binding, claim, and query predicates such as sd:bindingObject, sd:hasClaim, and sd:queryString).
Membership in this namespace is derived by the Lexicon from the declaration above — see Namespace Definition.