English: Document Type Definition
Welsh: Diffiniad o'r Math o Ddogfen
Subject: Cyffredinol
English definition: DTD. A file that defines how applications interpreting a document should present the works. Most notably used in conjunction with XML documents.
Welsh definition: Ffeil sy'n diffinio sut ddylai cymwysiadau sy'n dehongli dogfen gyflwyno'r gweithiau. Yn fwyaf nodedig, fe’i defnyddir ar y cyd â dogfennau XML.