From W3C Wiki
What are the useful minimal parts of RDF and XML?
Minimal useful XML
- XML declaration - content encoding(*) minimally, utf-8 suffices and doesn't need to be declared.
- (numeric?) character entities these are redundant, no?
- element names
- attribute names and values
- element content (PCDATA)
- namespaces minimally, not needed but may be modern XML good practice
Minimal useful RDF
- Unicode string literal (see also TextValues)
- blank node identifier
Minimal useful RDF/XML
- node element and rdf:about/rdf:nodeID
- property element and rdf:resource/rdf:nodeID
- literal content
This ignores describing languages, such as by xml:lang in XML.