The Markdown preferences page makes it possible to validate Markdown documents with Schematron. To access the page, open the Preferences dialog box and go to Markdown. This preferences page includes the following options:
If selected, converted HTML content will be validated using the Schematron file specified in this option.
The catalog mapping is a fallback in case the validation is disabled in this preferences page or the path to the Schematron is empty. The associations configured in this preferences page take precedence.