Markdown Support Arrives for Work Items - Azure DevOps Blog
Briefly

Markdown support in large text fields is now generally available, allowing users to opt-in for Markdown on new and existing work items. Users can click on large text fields to convert HTML to Markdown, though complex HTML may not convert accurately. Once converted, fields display text in Markdown format and cannot revert to HTML. New work items default to Markdown based on user preference. Pasting HTML into Markdown fields will attempt an automatic conversion as long as the field is still empty.
Markdown support for large text fields is now generally available, allowing users to opt-in for Markdown editing on new and existing work items.
Once a field is set to Markdown mode, it cannot be reverted back to HTML, so users should consider the necessity of the formatting before converting.
In new work items, the editor preference for Markdown is sticky, meaning future items will default to Markdown if selected initially.
Pasting HTML into the Markdown editor prompts an automatic conversion, but only if the field is still empty and not previously converted to Markdown.
Read at Azure DevOps Blog
[
|
]