Slack Message Formatting (mrkdwn)

When responding to Slack channels, use Slack's mrkdwn syntax instead of standard Markdown.

How to detect Slack context

Check your group folder name or workspace path:

• Folder starts with slack_ (e.g., slack_engineering, slack_general)
• Or check /workspace/group/ path for slack_ prefix

Formatting reference

Text styles

Links and mentions

<https://example.com|Link text>     # Named link
<https://example.com>                # Auto-linked URL
<@U1234567890>                       # Mention user by ID
<#C1234567890>                       # Mention channel by ID
<!here>                              # @here
<!channel>                           # @channel

Lists

Slack supports simple bullet lists but NOT numbered lists:

• First item
• Second item
• Third item

Use • (bullet character) or - or * for bullets.

Block quotes

> This is a block quote
> It can span multiple lines

Emoji

Use standard emoji shortcodes: :white_check_mark:, :x:, :rocket:, :tada:

What NOT to use

• NO ## headings (use *Bold text* for headers instead)
• NO **double asterisks** for bold (use *single asterisks*)
• NO [text](url) links (use <url|text> instead)
• NO 1. numbered lists (use bullets with numbers: • 1. First)
• NO tables (use code blocks or plain text alignment)
• NO --- horizontal rules

Example message

*Daily Standup Summary*

_March 21, 2026_

• *Completed:* Fixed authentication bug in login flow
• *In Progress:* Building new dashboard widgets
• *Blocked:* Waiting on API access from DevOps

> Next sync: Monday 10am

:white_check_mark: All tests passing | <https://ci.example.com/builds/123|View Build>

Quick rules

1. Use *bold* not **bold**
2. Use <url|text> not [text](url)
3. Use • bullets, avoid numbered lists
4. Use :emoji: shortcodes
5. Quote blocks with >
6. Skip headings — use bold text instead