This plugin addresses a specific issue where colons in fragments of relative URLs are removed during content saving in a CMS, which can break links in generated HTML such as those from Markdown Extra. It is designed for developers and content managers who use tools that produce HTML with colons in URL fragments, ensuring their links work correctly.

• Automatic colon replacement: Replaces colons with dashes in id and name attributes, and in href attributes of relative URLs, before content is processed and saved.
• Compatibility with HTML standards: Works with HTML4 and HTML5, where colons are allowed in fragments, preventing unnecessary removal that disrupts link functionality.
• Pre-save processing: Executes before other content filters run, ensuring the fix is applied early in the saving process to avoid conflicts.
• Minimal setup: Requires only copying a single file to the mu-plugins directory, making installation straightforward without complex configuration.
• Targeted solution: Specifically handles relative and protocol-relative URLs, leaving absolute URLs unaffected to maintain broader compatibility.