Rule - MD054

Property	Value
Aliases	md054, link-image-style
Autofix Available	No
Enabled By Default	Yes

Summary

Keep the style of links and images consistent within a Markdown document.

Reasoning

Consistency

Consistent link and image styles make a document easier to read and maintain. Restricting a document to a chosen subset of the six supported styles (autolink, inline link, full reference, collapsed reference, shortcut reference, and inline URL) reduces stylistic drift across a repository and helps readers recognize the same construct the same way.

Examples

Failure Scenarios

This rule triggers when an autolink (e.g., <https://example.com>) is used in a location where the autolinks configuration value is set to False.

<https://example.com>

Explanation: The example uses an autolink. If the autolinks configuration value is set to False, this autolink violates the rule because that style is disabled.

Unlike the previous example, this case uses an inline link and is triggered only when inline-links is set to False.

[link](https://example.com)

Explanation: The example uses an inline link. If the inline-links configuration value is set to False, this inline link violates the rule because the style is no longer permitted.

Unlike the previous example, this case uses a full reference link and is triggered only when full-links is set to False.

[link][url]

[url]: https://example.com

Explanation: The example uses a full reference link ([link][url] with a corresponding [url]: definition). If the full-links configuration value is set to False, this full reference link violates the rule because that style is disabled.

Unlike the two preceding examples, this case uses a collapsed reference link and is triggered only when collapsed-links is set to False.

[url][]

[url]: https://example.com

Explanation: The example uses a collapsed reference link ([url][]). If the collapsed-links configuration value is set to False, this collapsed reference link violates the rule because that style is disabled.

Unlike the preceding reference-link example, this case uses a shortcut reference link and is triggered only when shortcut-links is set to False.

[url]

[url]: https://example.com

Explanation: The example uses a shortcut reference link ([url]). If the shortcut-links configuration value is set to False, this shortcut reference link violates the rule because that style is disabled.

Unlike the previous reference-link example, this case uses an inline link whose label and URL are identical and is triggered only when inline-urls is set to False.

[https://example.com](https://example.com)

Explanation: The example uses an inline link whose label and URL are identical If the inline-urls configuration value is set to False, this self-referencing inline link violates the rule because that style is disabled.

Correct Scenarios

This rule does not trigger when an autolink (e.g., <https://example.com>) is used in a location where the autolinks configuration value remains True.

<https://example.com>

Explanation: The example uses an autolink. With the default configuration for autolinks set to True, autolinks are permitted, so the rule does not trigger on this construct.

Unlike the previous autolink example, this case uses an inline link and satisfies the rule as long as inline-links has not been disabled.

[link](https://example.com)

Explanation: The example uses an inline link. With the default configuration for inline-links set to True, inline links are permitted, so the rule does not trigger on this construct.

Unlike the preceding inline-link example, this case uses a full reference link and satisfies the rule as long as full-links has not been disabled.

[link][url]

[url]: https://example.com

Explanation: The example uses a full reference link with a matching link reference definition. With the default configuration of full-links set to True, full reference links are permitted, so the rule does not trigger.

Unlike the preceding full reference link, this case uses a collapsed reference link and satisfies the rule as long as collapsed-links has not been disabled.

[url][]

[url]: https://example.com

Explanation: The example uses a collapsed reference link. With the default configuration for collapsed-links set to True, collapsed reference links are permitted, so the rule does not trigger.

Unlike the preceding collapsed reference link, this case uses a shortcut reference ink and satisfies the rule as long as shortcut-links has not been disabled.

[url]

[url]: https://example.com

Explanation: The example uses a shortcut reference link. With the default configuration of shortcut-links set to True, shortcut reference links are permitted, so the rule does not trigger.

Unlike the preceding shortcut reference link, this case uses an inline link whose label and URL are identical and satisfies the rule as long as inline-urls has not been disabled.

[https://example.com](https://example.com)

Explanation: The example uses an inline link whose label and URL are identical. With the default configuration for inline-urls set to True, this style is permitted, so the rule does not trigger.

Fix Description

The tool cannot autofix this, because a non-permitted link or image could be rewritten into any of the other enabled styles (autolink, inline link, full reference, collapsed reference, shortcut reference, or inline URL). Choosing one replacement without author intent could change the meaning or emphasis of the document.

Configuration

Prefixes
plugins.md054.
plugins.link-image-style.

Value Name	Type	Default	Description
enabled	boolean	True	Whether the Rule Plugin is enabled.
autolinks	boolean	True	Whether autolinks are allowed.
inline-links	boolean	True	Whether inline links and images are allowed.
full-links	boolean	True	Whether full links and images are allowed.
collapsed-links	boolean	True	Whether collapsed links and images are allowed.
shortcut-links	boolean	True	Whether shortcut links and images are allowed.
inline-urls	boolean	True	Whether inline URLs for links and images are allowed.

Origination of Rule

This rule is largely inspired by the MarkdownLint rule MD054.