BB code is a lightweight markup language that lets you format text in forums, comments, and support tickets without using HTML. It uses simple tags enclosed in square brackets to control bold, italic, links, and more complex layouts.
Because BB code is plain text and easy to parse, it remains popular on platforms where full HTML is disabled for security or simplicity. Understanding core tags and best practices helps you write cleaner, more readable posts.
| Tag | Syntax | Rendered Output | Common Use |
|---|---|---|---|
| Bold | [b]text[/b] | text | Highlight key terms or titles |
| Italic | [i]text[/i] | text | Emphasize or reference titles |
| Underline | [u]text[/u] | text | Draw attention sparingly |
| Color | [color=blue]text[/color] | text | Organize categories or warnings |
| URL | [url]https://example.com[/url] | https://example.com | Share references and sources |
| [email]user@example.com[/email] | user@example.com | Enable direct contact | |
| List ordered | [list=1][*]item 1[*]item 2[/list] |
|
Step-by-step instructions |
| List unordered | [list][*]item 1[*]item 2[/list] |
|
Group related options |
Basic Syntax Rules and Tag Structure
BB code relies on opening and closing tags with a consistent structure. Most formatting tags follow the pattern [tag]content[/tag], and nesting is generally supported when platforms allow.
Always close tags in the reverse order they were opened to avoid broken rendering. For example, [b][i]bold italic[/i][/b] is valid, while mismatched closing tags can cause display issues.
Some tags accept parameters inside the opening tag, such as [color=red] or [url=https://site.com]. Place these values directly after the tag name and ensure quotes are used for URLs that include special characters.
Using BB Code in Forums and Comments
Forums and legacy systems often depend on BB code to prevent cross-site scripting while still giving users control over presentation. Knowing which tags are allowed reduces the need to switch to plain text mode.
Before posting, check the platform’s help section for a list of supported tags. Some boards disable advanced tags like [img] or [flash] to keep discussions focused and accessible.
Use line breaks and paragraph breaks deliberately. A wall of text with no spacing can reduce readability even when formatting is technically correct.
Best Practices for Readability and Accessibility
Prioritize clarity over decoration. Overuse of bright colors, underlines, and large fonts can make content harder to read for everyone.
Always include meaningful link text instead of raw URLs. Screen readers and mobile users benefit from descriptive labels like [url=https://docs.example.com]Documentation[/url] rather than [url]https://docs.example.com[/url].
Test your formatted post in preview mode to confirm lists, indentation, and spacing appear as expected across different devices and browsers.
Troubleshooting Common Rendering Issues
When formatting disappears, check for hidden characters or mismatched brackets. A single missing closing tag can cause the rest of the post to render as plain text.
Platform-specific quirks may affect uppercase vs lowercase tags. Write tags in lowercase to maximize compatibility unless documentation specifies otherwise.
Spam filters sometimes strip unknown attributes or inline styles. Stick to core tags like [b], [i], [url], and [list] to ensure your content reaches readers without modification.
Advanced Layout Techniques
Structured layouts improve scanning and comprehension. Use lists, consistent spacing, and clear headings to guide the reader through complex information.
- Use bold for section labels and key terms, not entire paragraphs
- Break long instructions into ordered steps with [list=1]
- Group related options with unordered [list] tags for clarity
- Add color sparingly to highlight warnings or categories
- Preview on multiple devices to verify responsive behavior
FAQ
Reader questions
Can I combine multiple formatting tags at once?
Yes, you can stack tags such as [b][i]text[/i][/b] to achieve bold italic formatting. Always close them in the reverse order to avoid rendering problems.
Why does my image tag not display correctly?
Images may fail to load if the URL is incorrect, the host blocks hotlinking, or the platform has disabled the [img] tag for security reasons.
Are there limits to how much I can format in a single post?
Excessive nesting and large numbers of inline images can slow down page loading and confuse readers. Use formatting purposefully and keep posts scannable.
Do mobile apps support the same BB code syntax?
Many mobile clients support the same core tags, but some platforms restrict advanced features or sanitize incoming content automatically.