Markdown is a simple formatting language invented by John Gruber that has gained in popularity over the past few years. It allows you to write in plain text, using some easily learned control characters, to produce nicely rendered HTML output. With some styling and ingenuity, you can create a wide variety of documents.

Markdown files can be imported or created via Data > New > Markdown text.

Editing: Writing Markdown is essentially the same as writing plain text documents. As you're writing you can switch easily between a plain text editor and the rendered view or even view both simultaneously using the side-by-side view via the View > Document Display commands.

When editing the source of the Markdown, DEVONthink's hybrid source rendering will display many types of formatting or elements as you type. For example, typing **important** will display the plain text in bold; `{"name":"Audrey Hepburn"}` will display as a code block, etc. If you'd prefer to see no formatting in the source code, you can disable WYSIWYG editing in Settings > Files > Markdown.

The currently supported WYSIWYG types, including CriticMarkup syntax, are:

File Transclusion: A special feature of DEVONthink's Markdown handling is support for file transclusion. This provides the capability of displaying the contents of one file inside the contents of a Markdown file. This supports displaying the contents of: plain text, rich text, HTML, formatted notes, sheet, or more commonly, other Markdown files. For example, you may have several chapters of a book written in individual Markdown files. Use transclusion to view them all as one document with out the need to merge or copy and paste the content between files, similar to some popular writing applications.

To use transclusion, just enter the desired document's name or item link between double braces, e.g., {{Chapter 1}}. Transclusion supports filenames with and without extensions, relative and absolute links, as well as item links. It also supports the Obsidian syntax, e.g., ![[Chapter 2.md]].

Styling: Styling your Markdown documents can be done with internal styling or externally referenced stylesheets. If you have a specific stylesheet you'd like to use globally, you can specify one in Settings > Files > Style Sheet.. Here are the options:

Linking: You can reference local images, scripts, and other resources using item links, downward-relative (traveling subgroups; it's not possible to travel up with '..' as documents can have multiple parents) or absolute (start with a forward slash) paths. Here are examples of linking an image:

Linking Images: Regarding keeping track of your linked images, if you drag or paste images into a Markdown document, they will be imported into a group in the document's location if Preference > Files > Markdown > Import images to group is enabled. The group name is also assigned in the preferences, with the default name being Assets. This group will also contain images from web content clipped as Markdown documents if the above option is enabled.

If you enter a name in the preferences mentioned above, this will create a subgroup in the location of the Markdown document and a relative link will be created in the Markdown document. If you add a name preceded by a forward slash, e.g., /Markdown, this will create a group in the root of the database and an item link placed into the Markdown text. You can even set a more precise location, e.g., /Inbox/Markdown/Images.

Linking Other File Types: If you have enabled automatic WikiLinks > Names & Aliases, documents can be detected as you write your Markdown. These WikiLinks are active when previewing the file and are also preserved in a website export or conversion to other formats.

Drag and drop items into a Markdown document to add the appropriate links. Drag and drop documents while holding ⌘-⌥ will create a URL with an item link. Dropping an image will create a properly formatted Markdown image link. Drop .mp3 or .mp4 files to insert a playable multimedia link.

Another option for inserting links into Markdown documents, Control-click while editing and choose Insert Link To from the context menu. A Markdown formatted link will be automatically inserted for you. For images, just add an exclamation point before the link if you want it to display in the rendered document.

You can learn more about Markdown and its syntax on Gruber's Markdown pages or the MultiMarkdown syntax guide.

Metadata: One of the features of MultiMarkdown is metadata headers. These allow you to add non-displaying information about the document, like authors, dates, and even linked stylesheets. To use the feature, format the first line of the document with a colon, e.g., Author: DEVONtechnologies. This must be the first line of the document. Other metadata fields you wish to add must follow immediately after this first line.

However, if you would like the first line of your document to contain a colon, perhaps adding notes like Developer: A. Edwards and Re: OCR, just add a single blank line at the top of the document and the subsequent lines will be treated as normal paragraphs.

Emoji: For a little extra personalization, you can type Slack-style emoji, like :grinning:, directly in the Markdown document.