(*<*) theory "00_Frontmatter" imports "Isabelle_DOF.technical_report" begin open_monitor*[this::report] (*>*) title*[tit::title]\The Isabelle/DOF User and Implementation Manual\ text*[adb:: author, email="\a.brucker@exeter.ac.uk\", orcid="\0000-0002-6355-1200\", http_site="\https://www.brucker.ch/\", affiliation="\University of Exeter, Exeter, UK\"]\Achim D. Brucker\ text*[bu::author, email = "\wolff@lri.fr\", affiliation = "\Université Paris-Saclay, LRI, Paris, France\"]\Burkhart Wolff\ text*[abs::abstract, keywordlist="[''Ontology'',''Ontological Modeling'',''Isabelle/DOF'']"]\ While Isabelle is mostly known as part of Isabelle/HOL (an interactive theorem prover), it actually provides a framework for developing a wide spectrum of applications. A particular strength of the Isabelle framework is the combination of text editing, formal verification, and code generation. Up to now, Isabelle's document preparation system lacks a mechanism for ensuring the structure of different document types (as, e.g., required in certification processes) in general and, in particular, mechanism for linking informal and formal parts of a document. In this paper, we present \isadof, a novel Document Ontology Framework on top of Isabelle. \isadof allows for conventional typesetting \<^emph>\as well\ as formal development. We show how to model document ontologies inside \isadof, how to use the resulting meta-information for enforcing a certain document structure, and discuss ontology-specific IDE support. \ (*<*) end (*>*)