3BL Content Editor: Formatting, Media & HTML Specifications

This guide provides a comprehensive overview of how the editor works, what it supports, and how to maximize performance and discoverability using structured content.
image of the 3BL content editor body
3BL's Content Editor

3BL Content Editor: Formatting, Media & HTML Specifications

The 3BL Editor is a structured, HTML-based publishing environment. Formatting is not decorative — it is a technical decision that affects how content is rendered, indexed, and distributed. This guide provides a comprehensive overview of how the editor works, what it supports, and how to maximize performance and discoverability using structured content.

Character Limits

Every field in the editor has a defined limit that affects how your content previews across channels — from email inboxes to aggregator feeds. These aren't soft guidelines; exceeding them causes truncation downstream.

Character Limits
Field Limit Notes
Headline 255 characters Target 60 for search display
Subheadline 255 characters Doubles as SEO meta description
Body No limit Full article content
Short teaser 280 characters Used in email distribution previews

Writing a headline under 60 characters isn't just an SEO best practice — it's the threshold at which most search engines display the full title without truncation. The 255-character field gives you flexibility, but 60 is the practical target.1

Supported HTML Elements

Text Structure & Semantics

Well-structured content starts with the right tags. Headings, paragraphs, and text formatting elements do more than control appearance — they signal hierarchy to the systems that distribute and index your content.

  • Bold signals importance to both readers and search systems.
  • Italic works well for titles or technical terms being introduced.
  • Underline is supported but use sparingly to avoid confusion with links.
  • Superscript and subscript render correctly for use cases like COCO or trademark symbolsTM -- both travel cleanly through distribution.

Lists

When sequence matters, use an ordered list:

  1. Lead with your most important claim in the headline and H1
  2. Support it with evidence in modular, self-contained sections
  3. Close with a clear takeaway or call to action
  4. Keep each section focused on one idea

When information is parallel but not sequential, use bullets:

  • Semantic headings at every major section break
  • Descriptive hyperlink anchor text
  • Alt text on every image
  • Embeds placed within the body, not isolated at the top or bottom

Links

The <a> tag supports href, alt, target, title, and rel attributes. Use descriptive anchor text for both accessibility and search performance. Read more about 3BL's framework for optimizing content in our 2026 LLM and Generative AI Writing Guide.

Content Sanitization & Unsupported Elements

The editor automatically removes unsupported or unsafe elements on save. The most common ones teams run into:

  • Special characters, emojis, and math symbols
  • <div> (except for specific oEmbed use cases)
  • <span>
  • <video>
  • <audio>
  • <iframe>

Formatting that looks correct in the editor can degrade silently on downstream endpoints. A table that renders cleanly on 3BL Media may lose its header row on a wire service. Test every rich element against your full distribution stack before publishing.

Rich Media: Embeds & Images

Video Embeds

oEmbed is supported for YouTube, Vimeo, DailyMotion, and Spotify. Place embeds within the body of the article for the best rendering consistency across endpoints.

Images

Supported formats are PNG and JPEG only, with a maximum file size of 100MB. Every image should include descriptive alt text.

Before vs After of 3BL's Content Editor with Images
A sample caption using figcaption. Captions are supported for images and render consistently across most endpoints.

Rich Content & Performance Considerations

Rich content affects rendering behavior, how information is consumed by search engines, accessibility, and consistency distributed across channels.

  • Your headline should clearly communicate what the content is about in less than 60 characters.
  • Use the description to add context about why this topic matters and why your organization is positioned to speak about it.
  • The first header (H1) should mirror your headline, using words that communicate authority or nod toward search intent.
  • Secondary headers (H2, H3) help break up your content — more readable to both humans and robots than a long unbroken block of text.
  • Keep each section modular, with one clear idea per section.
  • Add descriptive alt text to images to help visually impaired readers and AI systems interpret the visuals you use.

The 3BL Content Editor gives marketing, communications, and PR teams the creative flexibility to produce rich, multimedia-driven stories — while ensuring content is structured, sanitized, and distributed consistently across 3BL's network of 79 partner sites.

1Based on Google's standard search result title display behavior as of 2026.

 


 

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