📄📐🧱

#DTD #document structure #XML schema #SGML definition #markup rules #document grammar

</>🏗️📖

#DTD #XML DTD #SGML DTD #markup definition #element structure #attribute definition #markup language

🗺️<>➡️📄

#generalized markup #meta-language #document type definition #DTD #sgml grammar #markup specification

📄🏷️📖

#DTD #document classification #type definition #XML type #SGML type #document labeling